Semiconductor device and manufacturing method thereof

ABSTRACT

Such a device is disclosed that includes: redundancy circuits for replacing defective memory cells included in a memory cell array; an electrical fuse circuit that stores addresses of the defective memory cells; a data determination circuit that generates a determination signal by determining whether test data read from the memory cell array is correct or incorrect; and an analysis circuit that supplies, in a first operation mode, the electrical fuse circuit with an address signal supplied when the determination signal is activated, and supplies, in a second operation mode, the electrical fuse circuit with an address signal supplied when a data mask signal supplied from outside is activated irrespective of the determination signal.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 13/364,017 filed Feb. 1, 2012, which claims priority from JapanesePatent Application No. 2011-020539 filed Feb. 2, 2011, the disclosuresof which are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a semiconductor device and amanufacturing method thereof, and more particularly to a semiconductordevice in which defective memory cells can be replaced with redundantcells and a manufacturing method thereof.

2. Description of Related Art

Semiconductor memories typified by a DRAM (Dynamic Random Access Memory)include a large number of memory cells, some of which inevitably becomedefective due to manufacturing conditions and other factors. In order toship such semiconductor memories as conforming products, the redundancyrepair technique of replacing defective memory cells with redundantcells is needed.

According to the redundancy repair technique, a semiconductor memory ina wafer state is initially subjected to an operation test to detect theaddresses of defective memory cells (defect addresses). The detectedaddresses are programmed into optical fuses in the semiconductor memory.Optical fuses are fuses that can be blown by irradiation of a laser beamor the like. Since blown optical fuses cannot be restored to aconducting state again, it is possible to store information in anonvolatile and irreversible manner. When access is requested to theaddresses programmed in the optical fuses, redundant cells (alternativecells) are accessed instead of the defective memory cells, whereby theaddresses are repaired.

Memory cell defects occur mainly in the wafer stage (manufacturing stepsfor forming a plurality of circuits on a wafer; so-called front-endprocesses). Most defects are therefore repaired by replacement usingoptical fuses. However, new defects can occur after the replacementusing optical fuses, in back-end processes including assembly. Forexample, new defects may occur due to a thermal load during packaging.It is not possible to repair such defects by using the optical fuses.

As a solution to the problem, Japanese Patent Application Laid-Open No.2002-25289 and Japanese Patent Application Laid-Open No. 2007-328914propose semiconductor devices that can implement both the replacementusing optical fuses and replacement using electrical fuses.

Since the tester for use in the back-end processes needs to operate athigh speed, it is not realistic to mount a large-capacity analysismemory as with low-speed testers used in the wafer stage. In order toanalyze defects occurring in the back-end processes by using the tester,the number of semiconductor devices to be simultaneously tested needs tobe reduced. This has caused a problem of a significant drop inproduction efficiency.

Japanese Patent Application Laid-Open No. 2001-52497 describes a methodof compressing the amount of information related to defective memorycells by determining a plurality of defective memory cells detected tobe a line defect, not individual bit defects, if the defective memorycells fall on the same line.

The method described in Japanese Patent Application Laid-Open No.2001-52497, in short, is to handle a plurality of bit defects as a linedefect. Such a method can reduce the final amount of information,whereas it is hardly possible to reduce the work area needed for addressanalysis, i.e., the storage capacity of the analysis memory. The reasonis that information on a large number of bit defects needs to beretained before the determination of a line defect, depending on theorder of defective memory cells detected.

The present inventors have proposed a semiconductor device employing ananalysis circuit which analyzes a defective address. According to this,since a storage capacity required for an analysis memory can besignificantly reduced, the analysis memory can be integrated into thesemiconductor device. However, an operating speed at the time of a testwill be restricted by operating speeds of the analysis circuit and theanalysis memory in this case. In addresses of a semiconductor device, anaddress not to become defect at the time of low-speed access, but becomedefect at the time of high-speed access may exist. There is apossibility that such a defect cannot be discovered only by the test ofoperation using the internal analysis circuit and the analysis memory.Therefore, it is desirable to discover such a defect and to replace adefective cell by a redundant cell. The present invention is made basedon such technical findings.

SUMMARY

In one embodiment, there is provided a semiconductor device thatincludes: a memory cell array; a redundancy circuit that replacesdefective memory cells included in the memory cell array; an electricalfuse circuit that stores addresses of at least part of the defectivememory cells; a data determination circuit that activates adetermination signal when test data read from the memory cell array isincorrect; and an analysis circuit that supplies, in a first operationmode, an address of the test data to the electrical fuse circuit whenthe determination signal is activated, and supplies, in a secondoperation mode, the address of the test data to the electrical fusecircuit when a select signal supplied from outside is activatedirrespective of the determination signal.

In another embodiment, there is provided a semiconductor device thatincludes: a memory cell array that includes a plurality of word linesincluding first to third defective word lines, a plurality of bit linesincluding first to third defective bit lines, a plurality of redundantword lines replacing the first to third defective word lines, and aplurality of redundant bit lines replacing the first to third defectivebit lines; an optical fuse circuit that stores an address of the firstdefective word line and an address of the first defective bit line; anelectrical fuse circuit that stores an address of the second defectiveword line and an address of the second defective bit line; and ananalysis circuit that analyzes the addresses of the second defectiveword line and the second defective bit line based on test data read fromthe memory cell array with the first defective word line replaced withone of the redundant word lines and the first defective bit linereplaced with one of the redundant bit lines. The analysis circuitreceives an address of the third defective word line or an address ofthe third defective bit line from outside and supplying the address ofthe third defective word line or an address of the third defective bitline to the electrical fuse circuit with the first and second defectiveword lines replaced with ones of the redundant word lines and the firstand second defective bit lines replaced with ones of the redundant bitlines.

In one embodiment, there is provided a method of manufacturing asemiconductor device that includes: performing a first operation test ona memory device formed on a semiconductor wafer; analyzing addresses ofdefective memory cells detected by the first operation test to identifyfirst defective word lines and first defective bit lines; performingprimary replacement to replace the first defective word lines and thefirst defective bit lines with first redundant word lines and firstredundant bit lines, respectively; dicing the semiconductor wafer afterperforming the primary replacement to obtain a memory chip on which thememory device is integrated; packaging one or more semiconductor chipsincluding at least the memory chip to obtain a packaged semiconductordevice; performing a second operation test on the packaged semiconductordevice; analyzing addresses of defective memory cells detected by thesecond operation test to identify second defective word lines and seconddefective bit lines; and performing secondary replacement to replace thesecond defective word lines and the second defective bit lines withsecond redundant word lines and second redundant bit lines,respectively; performing a third operation test on the packagedsemiconductor device after performing the secondary replacement;analyzing an address of a defective memory cell detected by the thirdoperation test to identify a third defective word line or a thirddefective bit line; and performing tertiary replacement to replace thethird defective word line or the third defective bit line with a thirdredundant word line or a third redundant bit line, respectively. Theaddresses of the defective memory cells detected by the second operationtest are analyzed by an analysis circuit integrated into the packagedsemiconductor device. The address of the defective memory cell detectedby the third operation test is analyzed by an external tester connectedto the packaged semiconductor device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram indicative of a configuration of asemiconductor device 100 according to a preferred first embodiment ofthe present invention;

FIGS. 2A and 2B are schematic diagrams for explaining a function of arepair control circuit 140, FIG. 2A showing a part related toreplacement of word lines, FIG. 2B showing a part related to replacementof bit lines;

FIG. 3 is a schematic diagram indicative of a relation of connectionbetween the semiconductor device 100 and an external tester 200;

FIG. 4 is a circuit diagram of a mode select circuit 143 a which isincluded in an analysis circuit 143;

FIG. 5 is a flowchart for providing an overview of the steps formanufacturing the semiconductor device 100;

FIG. 6 is a schematic diagram for explaining a data structure of defectanalysis data to be stored in an analysis memory 144;

FIG. 7 is a chart for explaining types of error pattern information Dand definitions of the pieces of corresponding error address informationx0, y0, x1, y1, and z;

FIG. 8 is a chart indicative of an example of expression of the errorpattern information D in three bits of data;

FIG. 9 is a diagram indicative of a configuration of a repair unit arraywhich is composed of a plurality of memory mats;

FIG. 10 is a diagram indicative of an example of replacing a defectiveword line with a redundant word line;

FIG. 11 is a diagram indicative of an example of replacing a defectivebit line with a redundant word line;

FIGS. 12A and 12B are diagrams indicative of a first concrete example ofaddress analysis of defective memory cells, FIG. 12A showing thearrangement and the order of detection of defective memory cells, FIG.12B showing the process of updating defect analysis data each time adefective memory cell is detected;

FIGS. 13A and 13B are diagrams indicative of a second concrete exampleof address analysis of defective memory cells, FIG. 13A showing thearrangement and the order of detection of defective memory cells, FIG.13B showing the process of updating defect analysis data each time adefective memory cell is detected;

FIG. 14 is a flowchart for explaining an operation of an analysiscircuit 143 and corresponds to steps S7 and S8 of the flowchart shown inFIG. 5;

FIG. 15 is a chart indicative of the relationship of internal signalsgenerated in the analysis circuit 143 and the current error patterninformation D with the commands to be generated;

FIGS. 16A to 16E are diagrams indicative of various types of positionalrelationships between defective memory cells previously found and adefective memory cell newly found;

FIG. 17 is a chart for explaining the relationship between the commandtype and control flags to be generated;

FIG. 18 is a chart for explaining the relationship between the commandtype and content of update of defect analysis data FMI<i>;

FIG. 19 is a chart for explaining the relationship between the commandtype and content of update of defect analysis data FMI<iNull>, whereinthe defect analysis data FMI<iNull> is updated when the division flagFMIa_modify is activated;

FIG. 20 is a flowchart for explaining the operation of the externaltester 200 and the analysis circuit 143 during tertiary repair andcorresponds to steps S80 to S82 of the flowchart shown in FIG. 5;

FIG. 21 is a schematic block diagram for explaining a method ofperforming tertiary repair on a plurality of semiconductor devices 100in parallel;

FIG. 22 is a flowchart for explaining the operation when performingtertiary repair on a plurality of semiconductor devices 100 in parallel;

FIG. 23 is a schematic cross-sectional view provided to explain thestructure of a semiconductor device 10 according to the preferred secondembodiment of the present invention;

FIGS. 24A to 24C are diagrams indicative of the various types of throughsilicon vias TSV provided in a core chip;

FIG. 25 is a cross-sectional view indicative of the structure of thethrough silicon via TSV1 of the type shown in FIG. 24A;

FIG. 26 is a cross-sectional view indicative of the structure of thethrough silicon via TSV2 of the type shown in FIG. 24B;

FIG. 27 is a cross-sectional view indicative of the structure of thethrough silicon vias TSV3 of the type shown in FIG. 24C;

FIG. 28 is a schematic diagram explaining the cyclic connection of thethrough silicon vias TSV3;

FIG. 29 is a block diagram indicative of the circuit configuration ofthe semiconductor device 10;

FIG. 30 is a flowchart for explaining the method of replacing defectivecells included in the core chips CC0 to CC7;

FIG. 31 is a flowchart for explaining operations of steps S55 and S56(secondary repair) shown in FIG. 30 in more detail;

FIG. 32 is a flowchart for explaining operations of steps S57 and S58(tertiary repair) shown in FIG. 30 in more detail;

FIG. 33 is a flowchart for explaining an operation of loadingreplacement data programmed in an electrical fuse circuit 83;

FIG. 34 is a block diagram indicative of a configuration of theelectrical fuse circuit 83 in more detail;

FIG. 35 is a block diagram indicative of a configuration of a defectiveaddress latch circuit 56 in more detail;

FIG. 36 is another block diagram indicative of the configuration of thedefective address latch circuit 56 in more detail;

FIG. 37 is a block diagram indicative of the configuration of theelectrical fuse circuit 83 and the defective address latch circuit 56 inmore detail;

FIG. 38 is a diagram for explaining a relationship between order ofselection of optical fuse circuits 55 and order of selection of theelectrical fuse circuit 83;

FIG. 39 is a circuit diagram indicative of an example of an addresscomparison circuit 51 a and a select circuit 56 e; and

FIG. 40 is a circuit diagram indicative of another example of theaddress comparison circuit 51 a and the select circuit 56 e.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Preferred embodiments of the present invention will be explained belowin detail with reference to the accompanying drawings.

Referring now to FIG. 1, the semiconductor device 100 according to thepresent embodiment is a semiconductor memory integrated on one chip. Thesemiconductor device 100 includes a memory cell array 101 which isdivided into eight banks BANK0 to BANK7. The memory cell array 101includes a plurality of word lines WL and a plurality of bit lines BL,at the intersections of which memory cells MC are arranged. For the sakeof simplicity, FIG. 1 shows only one word line WL, one bit line BL, andone memory cell MC arranged at the intersection.

Among the plurality of word lines included in the memory cell array 101,defective word lines are replaced with redundant word lines which areincluded in a row redundancy circuit 102. Among the plurality of bitlines included in the memory cell array 101, defective bit lines arereplaced with redundant bit lines which are included in a columnredundancy circuit 103. As employed herein, a defective word line refersnot only to a word line that is itself defective, but also to one thatis not itself defective and such that one or a plurality of memory cellsto be selected by the word line is/are defective. Similarly, a defectivebit line refers not only to a bit line that is itself defective, butalso to one that is not itself defective and such that one or aplurality of memory cells connected to the bit line is/are defective.

A row access to the memory cell array 101 is performed by a row decoder104. The row decoder 104 decodes a row address XADD supplied from a rowaddress control circuit 110, and selects any one of the word linesincluded in the memory cell array 101 based on the result of decoding.If the row address XADD supplied from the row address control circuit110 coincides with a defective address retained in a repair controlcircuit 140, the row decoder 104 makes an alternate access to aredundant word line in the row redundancy circuit 102 instead of theword line in the memory cell array 101.

A column access to the memory cell array 101 is performed by a columndecoder 105. The column decoder 105 decodes a column address YADDsupplied from a column address control circuit 111, and selects any oneof column switches included in a column control circuit 107 based on theresult of decoding. The column switches are switches for connecting anyone of sense amplifiers included in a sense amplifier row 106 to thecolumn control circuit 107. If one of the switches becomes conducting, apredetermined bit line is connected to the column control circuit 107through a corresponding sense amplifier. If the column address YADDsupplied from the column address control circuit 111 coincides with adefective address retained in the repair control circuit 140, the columndecoder 105 makes an alternate access to a redundant bit line in thecolumn redundancy circuit 103 instead of the bit line in the memory cellarray 101.

An address A0 to A15 and a bank address BA0 to BA2 are supplied to therow address control circuit 110 and the column address control circuit111 through address terminals 112 and an address buffer 113. The addressA0 to A15 is used as a row address XADD or a column address YADD. Thebank address BA0 to BA2 is used to select the banks BANK0 to BANK7.

Aside from the address terminals 112, the semiconductor device 100 hascommand terminals 120, control terminals 121, and clock terminals 122.

The command terminals 120 are a group of terminals to which a rowaddress strobe signal /RAS, a column address strobe signal /CAS, a writeenable signal /WE, and a chip select signal /CS are supplied. Suchcommand signals input to the command terminals 120 are supplied to acommand decoder 124 and a mode register 125 through a command buffer123. The command decoder 124 is a circuit that decodes the commandsignals to generate internal commands and supplies the internal commandsto control logic 127 and the like. The mode register 125 is a registerwhose setting value can be rewritten with the address A0 to A15. Thesetting value is supplied to the control logic 127 and the like.

The control terminals 121 are a group of terminals that includes ones towhich a data mask signal DM, an on-die termination signal ODT, and areset signal /RESET are input, and a calibration terminal ZQ. Suchcontrol signals input to the control terminals 121 are supplied to thecontrol logic 127 through a control buffer 126. The control logic 127 isa circuit that generates various types of control signals based on thesupplied control signals, the internal commands, and the setting valueof the mode register 125. The control signals generated are supplied tothe row address control circuit 110, the column address control circuit111, and a data control circuit 108, and control the operations of suchcircuit blocks. The data mask signal DM is also supplied to an analysiscircuit 143 to be described later.

The clock terminals 122 are a group of terminals to which a clock signalCK, an inverted clock signal /CK, and a clock enable signal CKE aresupplied. Such clock signals input to the clock terminals 122 aresupplied to a clock generation circuit 129 through a clock buffer 128.The clock generation circuit 129 is a circuit that generates an internalclock signal based on the clock signal. The internal clock signalgenerated is supplied to various circuit blocks. Part of the internalclock signal is supplied to a DLL circuit 130. The DLL circuit 130 is acircuit that generates a phase-controlled clock for output based on theinternal clock signal. The generated clock for output is supplied to thedata control circuit 108 and an input/output buffer 109.

The data control circuit 108 is a circuit that latches read data outputin parallel through the column control circuit 107, converts the data toserial, and supplies the resultant to the input/output buffer 109. Thedata control circuit 108 also latches write data serially input throughthe input/output buffer 109, converts the data to parallel, and suppliesthe resultant to the column control circuit 107. The input/output buffer109 is connected to data system terminals 131. The data system terminals131 include data input/output terminals DQ0 to DQ7 and data strobeterminals DQS and /DQS. The data input/output terminals DQ0 to DQ7 areterminals for outputting read data and inputting write data. The datastrobe terminals DQS and /DQS are terminals for inputting and outputtingcomplementary data strobe signals.

With such a configuration, when a read command is input through thecommand terminals 120, a read operation is performed on memory cellsthat are specified by the address A0 to A15 and the bank address BA0 toBA2. The resulting read data is output through the data input/outputterminals DQ0 to DQ7. When a write command is input through the commandterminals 120, a write operation is performed on memory cells that arespecified by the address A0 to A15 and the bank address BA0 to BA2,whereby write data that is input through the data input/output terminalsDQ0 to DQ7 is written. In such a read and write operations, if a memorycell to be accessed is a defective memory cell, an alternate access ismade to the row redundancy circuit 102 or the column redundancy circuit103. As described above, the addresses of defective memory cells areretained in the repair control circuit 140.

Defective addresses which are retained in the repair control circuits140 are transferred from an optical fuse circuit 141 and an electricalfuse circuit 142. The optical fuse circuit 141 is a circuit that storesinformation by blowing fuse elements by laser beam irradiation. Theelectrical fuse circuit 142 is a circuit that stores information byapplication of a high voltage to fuse elements. The fuse elements toconstitute the electrical fuse circuit 142 are not limited inparticular, whereas it is preferred to use anti-fuse elements. Anti-fuseelements are elements that store information by the application of ahigh voltage to an insulating film for breakdown.

Turning to FIG. 2A, the repair control circuit 140 includes a pair oflatch circuits 151 and 152. A select circuit 153 selects defectiveaddresses retained in either one of the latch circuits 151 and 152. Thelatch circuit 151 is a circuit that latches defective addresses readfrom the optical fuse circuit 141. The latch circuit 152 is a circuitthat latches defective addresses read from the electrical fuse circuit142. The defective addresses selected by the select circuit 153 aresupplied to a determination circuit 104 a which is included in the rowdecoder 104. The determination circuit 104 a is a circuit that comparesthe defective addresses RXADD supplied from the repair control circuit140 with an access-requested row address XADD. If the addresses match,the determination circuit 104 a activates a hit signal HITX. The rowaddress XADD is also supplied to a decoder circuit 104 b. If the hitsignal HITX is not activated, a predetermined word line WL is selectedbased on the result of decoding of the decoder circuit 104 b. If the hitsignal HITX is activated, a redundant word line RWL is selectedregardless of the result of decoding of the decoder circuit 104 b. As aresult, the defective word line WL is replaced with the redundant wordline RWL.

The replacement of bit lines is similarly performed. As shown in FIG.2B, a select circuit 156 selects either one of the outputs of latchcircuits 154 and 155. The selected output is supplied to a determinationcircuit 105 a which is included in the column decoder 105. Thedetermination circuit 105 a is a circuit that compares defectiveaddresses RYADD supplied from the repair control circuit 140 with anaccess-requested column address YADD. If the addresses match, thedetermination circuit 105 a activates a hit signal HITY. If the hitsignal HITY is not activated, a predetermined column select line YS isselected based on the result of decoding of a decoder circuit 105 b. Ifthe hit signal HITY is activated, a redundant column select line RYS isselected regardless of the result of decoding of the decoder circuit 105b. As a result, defective bit lines corresponding to the column selectline YS are replaced with redundant bit lines corresponding to theredundant column select line RYS.

As described above, in the semiconductor device 100 according to thepresent embodiment, one redundant word line can be used by both theoptical fuse circuit 141 and the electrical fuse circuit 142. Similarly,one redundant bit line can be used by both the optical fuse circuit 141and the electrical fuse circuit 142. It will be understood that oneredundant word line or one redundant bit line is not simultaneouslyusable by the optical fuse circuit 141 and the electrical fuse circuit142. Redundant word lines and redundant bit lines are used for primaryrepair by the optical fuse circuit 141. Redundant word lines andredundant bit lines remaining unused in the primary repair are used forsecondary or tertiary repair by the electrical fuse circuit 142.

Detection of defective memory cells in the secondary repair, that is,true-false decision of test data are detected is performed by a datadetermination circuit 107 a which is included in the column controlcircuit 107. The resulting determination signal P/F is supplied to ananalysis circuit 143. The determination signal P/F indicates a “pass” ifread data contains no error, and a “fail” if read data contains anerror.

If the determination signal P/F indicates a “fail”, the analysis circuit143 refers to the accessed address to identify the address of thedefective memory cell, and analyzes the relationship with the addressesof defective memory cells that have previously been detected. Theoperation of the analysis circuit 143 will be described later. Theanalysis circuit 143 uses an analysis memory 144 for the analysisoperation. Although not limited in particular, the analysis memory 144is made of an SRAM. A storage capacity of the SRAM is only severalkilobits or so. The reason is that the analysis circuit 143 employs acharacteristic method of analysis which uses an extremely small workarea as will be described later. Aside from the determination signal P/Fand addresses, the analysis circuit 143 is supplied with an internalclock signal, an internal command, and control signals from a DFTcircuit 145.

The control signals supplied from the DFT circuit 145 to the analysiscircuit 143 include a mode select signal PT. The mode select signal PTis a signal that becomes low level when performing secondary repair, andbecomes high level when performing tertiary repair.

In tertiary repair, defective memory cells are detected by an externaltester 200 which is connected to the semiconductor device 100 as shownin FIG. 3. The resulting addresses that are determined to be defectiveare supplied from the external tester 200 to the semiconductor device100 through the address terminals 112. In tertiary repair, defectiveaddresses are supplied by using the data mask signal DM. The purpose isso that a single external tester 200 can be used to perform tertiaryrepair on a plurality of semiconductor devices 100 in parallel.Specifically, addresses that are supplied from the external tester 200in a period when the data mask signal DM is at a high level aredefective addresses. The defective addresses thus supplied from theexternal tester 200 are supplied to the analysis memory 144 through theanalysis circuit 143.

Turning to FIG. 4, the mode select circuit 143 a included in theanalysis circuit 143 includes a logic circuit that receives the datamask signal DM, the mode select signal PT, and the determination signalP/F to generate a determination signal PFR. With the circuitconfiguration shown in FIG. 4, the determination signal PFR has the samevalue as that of the determination signal P/F when the mode selectsignal PF is at a low level. This operation mode is intended forsecondary repair. The logic level of the data mask signal DM isirrelevant here. On the other hand, when the mode select signal PF is ata high level, the determination signal PFR has the same value as that ofthe data mask signal DM. This operation mode is intended for tertiaryrepair. The logic level of the determination signal P/F is irrelevanthere.

The determination signal PFR is a control signal for identifying anaddress signal that is supplied to the analysis circuit 143 as adefective address. When performing secondary repair (the mode selectsignal PT=low), defective addresses are fetched in response to thedetermination signal P/F. When performing tertiary repair (the modeselect signal PT=high), defective addresses are fetched in response tothe data mask signal DM.

Turning to FIG. 5, initially, in a front-end process (diffusionprocess), memory devices in a wafer state are fabricated (step S1). Thememory devices in the wafer state are subjected to an operation test(step S2). The operation test in step S2 is intended to detect theaddresses of defective memory cells in the wafer state. The operationtest is performed on a plurality of memory devices in parallel by usinga low-speed tester on which a large-capacity analysis memory is mounted.The addresses of the defective memory cells detected are analyzed in thetester, whereby defective word lines and defective bit lines areidentified (step S3). The addresses of the defective word lines and thedefective bit lines are then written into the optical fuse circuit 141by using a laser trimmer. As a result, the defective word lines and thedefective bit lines are replaced with redundant word lines and redundantbit lines (step S4). This completes the primary-repaired memory devicesin the wafer state.

Next, the wafer is diced into individual memory chips (step S5). Thememory chips are packaged into a semiconductor device 100 (step S6).Steps S5 and S6 belong to so-called back-end processes, which canproduce new defective memory cells due to a thermal load duringpackaging etc. After the packaging, it is no longer possible to repairsuch defects by using the optical fuse circuit 141. Post-packagingdefects are repaired by using the electrical fuse circuit 142 asdescribed below.

Initially, the semiconductor device 100 packaged is subjected to anoperation test to detect the addresses of defective memory cells (stepS7). The test is performed by writing and reading test data with themode register 125 set to a test mode for secondary repair, andoutputting the resulting determination signal P/F to the analysiscircuit 143. Specifically, if the determination signal P/F indicates afail, the analysis circuit 143 refers to the accessed address toidentify the defective word line and defective bit line (step S8). Here,the analysis circuit 143 updates error pattern information and erroraddress information each time a defective memory cell is detected. Theerror pattern information and the error address information are storedin the analysis memory 144.

The analysis circuit 143 then identifies the addresses of defective wordlines and defective bit lines from the final outcome of the errorpattern information and the error address information, and writes theaddresses into the electrical fuse circuit 142. As a result, thedefective word lines and the defective bit lines are replaced withredundant word lines and redundant bit lines (step S9). This completesthe secondary-repaired semiconductor device 100.

It should be noted that it is difficult to perform the operation testfor secondary repair at a designed maximum access speed, and the testspeed is limited by the operating speed of the data determinationcircuit 107 a, the analysis circuit 143, and the analysis memory 144.The access speed during secondary repair is sufficiently high ascompared to the access speed during primary repair, but is lower thanthe designed maximum access speed. In some rare instances, an addressthat is not found to be defective in an operation test during secondaryrepair can be defective under fast access. It is not possible to relievesuch an address by secondary repair. In view of this, the presentembodiment performs tertiary repair after secondary repair.

In tertiary repair, an operation test is performed on thesecondary-repaired semiconductor device 100 to detect the address of anydefective memory cell (step S80). The test is performed by writing andreading test data in the state where a test mode for tertiary repair isset to the mode register 125. The external tester 200 shown in FIG. 3evaluates the resulting read data DQ to analyze defective addresses(step S81). The access condition in tertiary repair is the same as in anormal operation. This allows access at the maximum design speed.Completing the analysis of defective addresses, the external tester 200inputs the defective addresses into the semiconductor device 100 byusing address signals and the data mask signal DM. As a result,defective word lines or defective bit lines are replaced with redundantword lines or redundant bit lines (step S82). This completes atertiary-repaired memory device 100.

In fact, very few defective addresses are found by tertiary repair. Thenumber of addresses found is mostly zero or only one if any. Besides,most of defective addresses founded by tertiary repair belong todiscrete bit defects, hardly a word line defect or bit line defect. Thereason is that word line or bit line defects have already been found andreplaced by primary repair and secondary repair. A bit defect found bytertiary repair, if any, can thus be relieved by replacing a word lineor bit line corresponding to that memory cell.

Since the number of defective addresses to be detected by tertiaryrepair is extremely small, the external tester 200 in use needs nohigh-capacity high-speed memory and has only to be capable of storingseveral defective addresses at maximum.

As described above, according to the present embodiment, the primaryrepair is performed in the wafer state, and the secondary repair and thetertiary repair are performed after the packaging. The redundant wordlines and redundant bit lines formed in the semiconductor device 100 canbe used for any of the primary repair, the secondary repair and thetertiary repair. It is therefore not needed to provide redundancycircuits dedicated to the secondary repair and redundancy circuitsdedicated to the tertiary repair. Moreover, in the secondary repair, theaddresses of defective memory cells are analyzed by using the analysiscircuit 143 and the analysis memory 144 which are included in thesemiconductor device 100. This eliminates the need to provide suchfunctions for the external tester and the like. In tertiary repair, theaddresses of defective memory cells are analyzed by using the externaltester 200 that is connected to the semiconductor device 100. This makesit possible to replace defective cells that occur only under fastaccess.

In the secondary repair, the error pattern information and the erroraddress information are updated each time a defective memory cell isdetected. The analysis memory 144 therefore needs a significantly smallstorage capacity as compared to the case with a method of simplyrecording the addresses of defective memory cells each time. Now, theoperation of the analysis circuit 143 to update the error patterninformation and the error address information will be described indetail.

Turning to FIG. 6, a plurality of pieces of defect analysis data FMI<0>to FMI<N> are stored in the analysis memory 144. The pieces of defectanalysis data FMI<0> to FMI<N> each include error pattern information Dand error address information x0, y0, x1, y1, and z. The error patterninformation D is stored in the register 144 a included in the analysismemory 144. The error address information x0, y0, x1, y1, and z isstored in additional register 144 b included in the analysis memory 144.In the following description, the contents of the jth piece of defectanalysis data FMI<j> will sometimes be expressed as:

FMI<j>={D,x0,y0,x1,y1,z}.

The error pattern information D is information that indicates therelative arrangement relationship of one or a plurality of defectivememory cells. The error address information x0, y0, x1, y1, and zincludes pieces of information that indicate the addresses of at leastpart of the defective memory cell(s) that is/are associated with theerror pattern information D. The error pattern information D and theerror address information x0, y0, x1, y1, and z will be described indetail below.

Turning to FIG. 7, error pattern information D is set to any one of theeight patterns. The first pattern is called a “Null” pattern, which isset when there is no defective memory cell assigned. In other words, theNull pattern indicates that the piece of defect analysis data FMI isunused.

The second pattern is called an “Sn” pattern. The Sn pattern is set whenthere is assigned one defective memory cell. In such a case, the rowaddress of the defective memory cell is set into the address x0 of theerror address information. The column address of the defective memorycell is set into the address y0. The address x1 and the address y1 areunused. The address of a memory mat to which the defective memory cellbelongs is set into the address z.

The third pattern is called a “Bx” pattern. The Bx pattern is set whenthere are assigned two defective memory cells that belong to the samerow address. In such a case, the row address and column address of onedefective memory cell 1 are set into the addresses x0 and y0 of theerror address information, respectively. The row address and columnaddress of the other defective memory cell 2 are set into the addressesx1 and y1, respectively. The address of the memory mat to which thedefective memory cells belong is set into the address z. The fourthpattern is called a “By” pattern. The By pattern is set when there areassigned two defective memory cells that belong to the same columnaddress. The definitions of the error address information are the sameas with the Bx pattern.

The fifth pattern is called a “Tr” pattern. The Tr pattern is set whenthree defective memory cells are arranged in an L shape. Specifically,as shown in FIG. 7, the defective memory cell 1 and the defective memorycell 3 have the same row address. The defective memory cell 1 and thedefective memory cell 2 have the same column address. In such a case,the row address and column address of the defective memory cell 1 areset into the addresses x0 and y0 of the error address information,respectively. The row address of the defective memory cell 2 is set intothe address x1. The column address of the defective memory cell 3 is setinto the address y1. The address of the memory mat to which thedefective memory cells belong is set into the address z.

The sixth pattern is called as “Sq” pattern. The Sq pattern is set whenfour defective memory cells are arranged in a rectangular shape.Specifically, as shown in FIG. 7, the defective memory cell 4 is addedto the Tr pattern. The defective memory cell 2 and the defective memorycell 4 have the same row address. The defective memory cell 3 and thedefective memory cell 4 have the same column address. In such a case,the row address and column address of the defective memory cell 1 areset into the addresses x0 and y0 of the error address information,respectively. The row address and column address of the defective memorycell 4 are set into the addresses x1 and y1, respectively. In otherwords, the addresses of the defective memory cells 1 and 4 at thediagonal positions are set. The address of the memory mat to which thedefective memory cells belong is set into the address z.

The seventh pattern is called a “Cx” pattern. The Cx pattern is set whenthree or more defective memory cells belonging to the same row addressare assigned in a line. In such a case, the row address and columnaddress of the defective memory cell 1 that has a smallest columnaddress value are set into the addresses x0 and y0 of the error addressinformation, respectively. The row address and column address of thedefective memory cell 3 that has a largest column address value are setinto the addresses x1 and y1, respectively. In other words, theaddresses of the defective memory cell 2 that comes between suchdefective memory cells 1 and 3 are omitted. The address of the memorymat to which the defective memory cells belong is set into the addressz.

The eighth pattern is called a “Cy” pattern. The Cy pattern is set whenthree or more defective memory cells belonging to the same columnaddress are assigned in a line. In such a case, the row address andcolumn address of the defective memory cell 1 that has a smallest rowaddress value are set into the addresses x0 and y0 of the error addressinformation, respectively. The row address and column address of thedefective memory cell 3 that has a largest row address value are setinto the addresses x1 and y1, respectively. In other words, theaddresses of the defective memory cell 2 that comes between suchdefective memory cells 1 and 3 are omitted. The address of the memorymat to which the defective memory cells belong is set into the addressz.

Since any one of the eight patterns is set as the error patterninformation D, the error pattern information D has only to have threebits. Turning to FIG. 8, as for error address information, bits as manyas needed to specify a row address are allocated to the addresses x0 andx1. Bits as many as needed to specify a column address are allocated tothe addresses y0 and y1. Bits as many as needed to specify a memory matare allocated to the address z. Now, the necessity of the use of theaddress z will be described.

Turning to FIG. 9, each single block represents a memory mat. Memorymats are areas that are defined by the range of word lines or the rangeof row addresses allocated for a single bit line, and the range of bitlines or the range of column addresses allocated for a single word line.In the example shown in FIG. 9, 512 word lines and 1024 bit lines areallocated to a single memory mat. That is, each memory mat has a storagecapacity of 512 Kbits. Among the memory mats shown in FIG. 9, hatchedones represent memory mats to which eight redundant word lines areadded. Forty-eight redundant bit lines are also added to each memorymat. Such memory mats are arranged in a matrix, 32 in a row directionand 8 in a column direction. A total of 256 mats constitute a singlerepair unit array. The number of bits of the repair unit array includingredundant memory cells is thus 16448×8576, which allows use as a128-Mbit array. A 128-Mbit repair unit array is equivalent to a bank ofa 1-Gbit memory chip, and one half bank of a 2-Gbit memory chip.

In the repair unit array, defective word lines can be flexibly replacedacross memory mats. Specifically, suppose, as shown in FIG. 10, that aword line WL0 is defective and memory mats to which the word line WL0belongs have no redundant word line. Even in such a case, the defectiveword line WL0 can be replaced with a redundant word line RWL0 thatbelongs to other memory mats.

In contrast, each memory mat includes redundant bit lines. As shown inFIG. 11, a defective bit line BL0 is thus replaced with a redundant bitline RBL0 in the same memory mat. DDR3 (Double Data Rate 3) SDRAMs use aso-called 8-bit prefetch system, in which data as much as eightaddresses is input or output to/from memory cells by a single access.For the sake of simple circuit configuration, the repair control circuit140 mostly employs the configuration of replacing entire data as much aseight addresses if any one of the addresses is defective. While a memorymat includes 48 redundant bit lines, the number of addresses actuallyrepairable is thus six (=48/8). In the example shown in FIG. 11, thenumber of bits of data to be simultaneously input or output from/tooutside is eight (DQ0 to DQ7). For simple circuit configuration, therepair control circuit 140 mostly employs the configuration of replacingall such eight bits if any one of the bits is defective.

The foregoing is the configuration of the repair unit array. Since thememory mats include 512 word lines and 1024 bit lines each, the rowaddress needed to specify a word line in a memory mat is in nine bits(X0 to X8). The column address needed to specify a bit line in a memorymat is in ten bits (Y0 to Y9). In fact, in the system of prefetchingdata as much as eight addresses by a single access as with DDR3 SDRAMs,the lower three bits (Y0 to Y2) of the column addresses needed tospecify the eight addresses will not be used in accessing within amemory mat. The column address actually needed to specify a bit line ina memory mat is thus in seven bits (Y3 to Y9). The lower three bits (Y0to Y2) of the column address is used in the data control circuit 108.

In the present embodiment, a plurality of defective memory cells thatare associated with a piece of error pattern information D need to be inthe same memory mat. The information for specifying the memory mat isthe address z which is included in the error address information. Theaddress z consists of the upper five bits of the row address (X9 toX13). The address z indicates a single partition of defect analysis dataFMI. A defective address is thus analyzed within the partition, notacross partitions.

As described above, error address information includes the followingaddresses: 9-bit addresses x0 and x1 which consist of a row address X0to X8 each; 7-bit addresses y0 and y1 which consist of a column addressY3 to Y9 each; and a 5-bit address z which consist of a row address X9to X13. The number of bits of error address information is thus 37.Since the number of bits of error pattern information D is three asmentioned above, a single piece of defect analysis data FMI has only tohave 40 bits. For example, if eight pieces of defect analysis data FMIare provided for each bank, the storage capacity of the analysis memory144 is 320 bits per bank.

As described above, according to the present embodiment, the relativearrangement relationship between defective memory cells in a memory matis expressed by error pattern information D, and error addresses foreach error pattern are expressed in a minimum number of bits.Consequently, the analysis memory 144 has only to have an extremelysmall number of bits.

For example, if defective memory cells included in a memory mat (z=0)have the pattern of FIG. 12A, only two pieces of defect analysis dataFMI<0> and FMI<1> need to be used. As shown in the final step of FIG.12B (step S39), the defect analysis data FMI<0> and FMI<1> results inthe following values:

FMI<0>={Cy,4,3,E,3,0},

and

FMI<1>={Cx,6,6,6,C,0}.

The process of obtaining the values will be described later.

In another example, if defective memory cells included in a memory mat(z=0) have the pattern of FIG. 13A, only three pieces of defect analysisdata FMI<0>, FMI<1>, and FMI<2> need to be used. As shown in the finalstep of FIG. 13B (step S49), the defect analysis data FMI<0>, FMI<1>,and FMI<2> results in the following values:

FMI<0>={Cx,4,1,4,D,0},

FMI<1>={Cx,7,1,7,B,0},

and

FMI<2>={Sn,1,1,0,0,0}.

The process of obtaining the values will also be described later.

Turning to FIG. 14, initially, the analysis circuit 143 enters the testmode (step S10). This activates the data determination circuit 107 a inthe column control circuit 107, whereby the data determination circuit107 a is switched into a mode of outputting the determination signalP/F. The contents of the analysis memory 144, an index i of the defectanalysis data FMI, and an index iNull of unused defect analysis data FMIare initialized (step S11). Next, the analysis circuit 143 reads andwrites a test pattern to perform an operation test (step S12). Theanalysis circuit 143 performs the operation test in succession whilechanging addresses as long as the determination signal P/F indicates apass (steps S13 to S15).

If the determination signal P/F indicates a fail (step S13: Fail), theanalysis circuit 143 loads the currently-selected defect analysis dataFMI<i> (step S20) and issues a command (step S21). In an initial state,the defect analysis data FMI<0> is selected. The command will bedescribed in detail later. If the issued command is an exit command(step S22: Yes), the analysis circuit 143 returns to step S14 becausethe failed address is already included in the defect analysis dataFMI<i>. On the other hand, if the issued command is neither the exitcommand (step S22: No) nor a nop command (step S23: No), the analysiscircuit 143 determines whether or not to issue an update command (stepS24). There are a plurality of update commands, which will also bedescribed later.

If the analysis circuit 143 determines to issue an update command (stepS24: Yes), the analysis circuit 143 updates the contents of the currentdefect analysis data FMI<i> according to the type of the command (stepS25). The defect analysis data FMI<i> may be updated by using anotherpiece of defect analysis data FMI<iNull> if needed. In such a case, theerror pattern that has been expressed by a single piece of error patterninformation D is expressed by two pieces of error pattern information D.One of the two error patterns is recorded by updating the defectanalysis data FMI<i>. The other is newly recorded by using the unuseddefect analysis data FMI<iNull>. The analysis circuit 143 may sort thepieces of defect analysis data FMI<0> to FMI<n> if needed. The analysiscircuit 143 then returns to step S14.

If the issued command is the nop command (step S23: Yes), the analysiscircuit 143 proceeds to the comparison of the next piece of defectanalysis data FMI<i+1> because the currently-selected defect analysisdata FMI<i> need not be updated. Here, the analysis circuit 143 selectsthe defect analysis data FMI<i+1> (step S27), and returns to step S20.If i=N (step S26: Yes), it is determined that relief is impossible (stepS28) because there is no defect analysis data FMI unused. The overflowprocessing, which will be described in detail later, is to determinewhether or not the error pattern information D can be reordered tosecure an unused piece of defect analysis data FMI available.

The analysis circuit 143 performs the foregoing operation each time thedetermination signal P/F indicates a fail. If all the addresses aretested (step S14: Yes), the series of test operations are ended. Thetest pattern may be an arbitrary pattern. A plurality of test patternsmay be used for the operation test. In fact, it is preferred to pick upa test pattern that provides a high defective rate in a screeningprocess, and perform the steps shown in FIG. 14 and the replacementoperation (step S9) before the test.

Next, various types of commands to be generated in the analysis circuit143 will be described.

Turning to FIG. 15, the field “D” shows the current error patterninformation. “xeq0,” “yeq0,” “xeq1,” “yeq1,” and “zeq” representinternal signals that are activated to a high level (1 in logical value)if the addresses of a newly-found defective memory cell, that is, theaddresses when the determination signal P/F indicates a fail coincide orare considered to coincide with the addresses x0, y0, x1, y1, and z thatconstitute the error address information, respectively. “Ovf” representsan overflow signal. The exit command is forcibly issued when theoverflow signal Ovf is at a high level. The nop command is forciblyissued when the internal command zeq is at a low level, since thedefective memory cell detected belongs to a memory mat different fromthe memory mat in question.

Initially, if the error pattern information D is “Null” when a defectivememory cell is found, a null_to_sn command is issued. The null_to_sncommand is a command to change the error pattern information D from theNull pattern to the Sn pattern.

If the error pattern information D is “Sn” when a defective memory cellis found in the same memory mat (zeq=1), different commands are issueddepending on the addresses. Specifically, suppose, as shown in FIG. 16A,that the current error pattern information D (=Sn) indicates that thereis a defective memory cell MC0. When a defective memory cell MC1 havingthe same row address as the associated address x0 is detected, theinternal signal xeq0 is activated to the high level and an sn_to_bxcommand is issued. The sn_to_bx command is a command to change the errorpattern information D from the Sn pattern to the Bx pattern. When adefective memory cell MC2 having the same column address as the addressy0 is detected, the internal signal yeq0 is activated to the high leveland an sn_to_by command is issued. The sn_to_by command is a command tochange the error pattern information D from the Sn pattern to the Bypattern.

On the other hand, if the error pattern information D is “Sn” whenneither of the internal signals xeq0 and yeq0 is activated, it meansthat as shown in FIG. 16A, the found defective memory cell MC3 lies in adiagonal position with respect to the defective memory cell MC0. In sucha case, the nop command is issued since it is not possible to integratethe information on the defective memory cells into the same piece ofdefect analysis data FMI. If both the internal signals xeq0 and yeq0 areactivated, the exit command is issued since it means that the samedefective memory cell MC0 is detected again. Whenever the same defectivememory cell is detected again, the exit command is issued. Redundantdescription will thus be omitted.

If the error pattern information D is “Bx” when a defective memory cellis found in the same memory mat (zeq=1), different commands are issueddepending on the addresses. Specifically, suppose, as shown in FIG. 16B,that the current error pattern information D (=Bx) indicates that thereare defective memory cells MC0 and MC1. When a defective memory cell MC2having the same row address as the associated address x0 is detected,the internal signal xeq1 is activated to the high level and a bx_to_cxcommand is issued. The bx_to_cx command is a command to change the errorpattern information D from the Bx pattern to the Cx pattern. When adefective memory cell MC3 having the same column address as the addressy0 is detected, the internal signal yeq0 is activated to the high leveland a bx_to_tr1 command is issued. The bx_to_tr1 command is a kind ofcommand to change the error pattern information D from the Bx pattern tothe Tr pattern. When a defective memory cell MC4 having the same columnaddress as the address y1 is detected, the internal signal yeq1 isactivated to the high level and a bx_to_tr2 command is issued. Thebx_to_tr2 command is a kind of command to change the error patterninformation D from the Bx pattern to the Tr pattern.

On the other hand, if none of the internal signals xeq0, yeq0, and yeq1is activated when the error pattern information D is “Bx”, it means thatas shown in FIG. 16B, the found defective memory cell MC5 is not relatedto any of the error address information x0, y0, and y1. In such a case,the nop command is issued since it is not possible to integrate theinformation on the defective memory cells into the same piece of defectanalysis data FMI. The exit command is issued in the cases previouslydiscussed.

If the error pattern information D is “By” when a defective memory cellis found in the same memory mat, similar operations will be performed aswith the case when the error pattern information D is “Bx”.

If the error pattern information D is “Tr” when a defective memory cellis found in the same memory mat (zeq=1), different commands are issueddepending on the addresses. Specifically, suppose, as shown in FIG. 16C,that the current error pattern information D (=Tr) indicates that thereare defective memory cells MC0 to MC2. When a defective memory cell MC3specified by the associated addresses x1 and y1 is detected, theinternal signals xeq1 and yeq1 are activated to the high level and atr_to_sq command is issued. The tr_to_sq command is a command to changethe error pattern information D from the Tr pattern to the Sq pattern.When a defective memory cell MC4 having the same row address as theaddress x0 is detected, the internal signal xeq0 is activated to thehigh level and a tr_to_sncx command is issued. The tr_to_sncx command isa command to change the error pattern information D from the Tr patternto the Cx pattern as well as to use a new piece of defect analysis dataFMI and set its error pattern information D to the Sn pattern. When adefective memory cell MC5 having the same column address as the addressy0 is detected, the internal signal yeq0 is activated to the high leveland a tr_to_sncy command is issued. The tr_to_sncy command is a commandto change the error pattern information D from the Tr pattern to the Cypattern as well as to use a new piece of defect analysis data FMI andset its error pattern information D to the Sn pattern.

On the other hand, suppose that the error pattern information D is “Tr”,neither of the internal signals xeq0 and yeq0 is activated, and at leasteither one of the internal signals xeq1 and yeq1 is not activated. Thismeans that as shown in FIG. 16C, the found defective memory cell MC6 isneither related to any of the error address information x0 and y0 norlies in the position of the memory cell MC3. In such a case, the nopcommand is issued since it is not possible to integrate the informationon the defective memory cells into the same piece of defect analysisdata FMI. The exit command is issued in the cases previously discussed.

If the error pattern information D is “Sq” when a defective memory cellis found in the same memory mat (zeq=1), different commands are issueddepending on the addresses. Specifically, suppose, as shown in FIG. 16D,that the current error pattern information D (=Sq) indicates that thereare defective memory cells MC0 to MC3. When a defective memory cell MC4or MC5 having the same row address as the associated address x0 or x1 isdetected, the internal signal xeq0 or xeq1 is activated to the highlevel and an sq_to_bxcx1 command or sq_to_bxcx2 command is issued. Thesq_to_bxcx1 command and the sq_to_bxcx2 command are commands to changethe error pattern information D from the Sq pattern to the Cx pattern aswell as to use a new piece of defect analysis data FMI and set its errorpattern information D to the Bx pattern. When a defective memory cellMC6 or MC7 having the same column address as the address y0 or y1 isdetected, the internal signal yeq0 or yeq1 is activated to the highlevel and an sq_to_bycy1 command or sq_to_bycy2 command is issued. Thesq_to_bycy1 command and the sq_to_bycy2 command are commands to changethe error pattern information D from the Sq pattern to the Cy pattern aswell as to use a new piece of defect analysis data FMI and set its errorpattern information D to the By pattern.

On the other hand, if the error pattern information D is “Sq” and noneof the internal signals xeq0, yeq0, xeq1, and yeq1 is activated, itmeans that as shown in FIG. 16D, the found defective memory cell MC8 isnot related to any of the error address information x0, y0, x1, and y1.In such a case, the nop command is issued since it is not possible tointegrate the information on the defective memory cells into the samepiece of defect analysis data FMI. The exit command is issued in thecases previously discussed.

If the error pattern information D is “Cx” when a defective memory cellis found in the same memory mat (zeq=1), different commands are issueddepending on the addresses. Specifically, suppose, as shown in FIG. 16E,that the defect analysis data FMI indicates that there are defectivememory cells MC0 to MC2. When a defective memory cell MC3 or MC4 havingthe same row address as the address x0 is detected, the internal signalxeg0 is activated to the high level and a cx_to_cx command is issued.The cx_to_cx command is a command to maintain the error patterninformation D as Cx. The memory cell MC3 shown in FIG. 16E applies to acase where its column address falls between the column address ymin ofthe memory cell MC0 and the column address ymax of the memory cell MC2.In contrast, the memory cell MC4 shown in FIG. 16E applies to a casewhere its column address does not come between the column address yminof the memory cell MC0 and the column address ymax of the memory cellMC2. If a defective memory cell lying outside the range of columnaddresses ymin and ymax is detected like the memory cell MC4, the erroraddress information is rewritten as will be described later.

On the other hand, if the error pattern information D is “Cx” and theinternal signal xeg0 is not activated, it means that as shown in FIG.16E, the found defective memory cell MC5 is not related to the erroraddress information x0. In such a case, the nop command is issued sinceit is not possible to integrate the information on the defective memorycells into the same piece of defect analysis data FMI. The exit commandis issued in the cases previously discussed.

If a defective memory cell is found when the error pattern information Dis “Cy”, similar operations will be performed as with the case when theerror pattern information D is “Cx.”

Turning to FIG. 17, there are four types of control flags. A firstcontrol flag is an increment flag iNull_inc. The activation of theincrement flag iNull_inc increments the index iNull, which indicates anunused piece of defect analysis data FMI, to iNull+1. A second controlflag is a division flag FMIa_modify. The activation of the division flagFMIa_modify updates the unused defect analysis data FMI<iNull>. Theincrement flag iNull_inc and the division flag FMIa_modify are activatedupon issuance of the tr_to_sncx command, tr_to_sncy command, sq_to_bxcx1command, sq_to_bxcx2 command, sq_to_bycy1 command, and sq_to_bycy2command. The increment flag iNull_inc is also activated upon issuance ofthe null_to_sn command.

A third control flag is an update flag FMI_modify. The activation of theupdate flag FMI_modify updates the current defect analysis data FMI<i>.The update flag FMI_modify is activated in response to all the commandsexcept the exit command and the nop command.

A fourth control flag is a reorder flag ReOrder. When the reorder flagReOrder is activated, the defect analysis data is sorted to shift thecurrent defect analysis data FMI<i> to a lower order. The reorder flagReOrder is activated when the division flag FMIa_modify is activated, aswell as when the bx_to_cx command or by_to_cy command is issued.

Turning to FIG. 18, the defect analysis data FMI<i> is updated when theupdate flag FMI_modify is activated. As mentioned above, the update flagFMI_modify is activated in response to all the commands except the exitcommand and the nop command.

In FIG. 18, the field “D_next” shows the updated error patterninformation D. The fields “x0_next”, “y0_next”, “x1_next”, “y1_next”,and “z_next” show the updated addresses x0, y0, x1, y1, and z,respectively. The notations “xC”, “yC”, and “zC” represent the rowaddress, column address, and memory mat address of the found defectivememory cell, respectively. The notations “xmin” and “xmax” representaddresses that have the smallest value and the largest value,respectively, among the row addresses included in the defect analysisdata. Similarly, the notations “ymin” and “ymax” represent addresseshaving the smallest value and the largest value, respectively, among thecolumn addresses included in the defect analysis data.

Initially, when the null_to_sn command is issued, the error patterninformation D is updated to “Sn”. The row address xC and column addressyC of the defective memory cell are written into the addresses x0 andy0. The addresses x1 and y1 are kept at the previous values and notupdated. In FIG. 18, the notations “x1” and “y1” mean that the previousvalues of “x1” and “y1” are given. The same holds for “x0” and “y0”.

When the sn_to_bx command is issued, the error pattern information D isupdated to “Bx”. The row address xC and column address yC of thedefective memory cell are written into the addresses x1 and y1. Theaddresses x0 and y0 are kept at the previous values and not updated.Similarly, when the sn_to_by command is issued, the error patterninformation D is updated to “By”. The row address xC and column addressyC of the defective memory cell are written into the addresses x1 andy1. The addresses x0 and y0 are kept at the previous values and notupdated.

When the bx_to_cx command is issued, the error pattern information D isupdated to “Cx”. The minimum value ymin and the maximum value ymax ofthe column addresses are written into the addresses y0 and y1,respectively. The addresses x0 and x1 are kept at the previous valuesand not updated. Similarly, when the by_to_cy command is issued, theerror pattern information D is updated to “Cy”. The minimum value xminand the maximum value xmax of the row addresses are written into theaddresses x0 and x1, respectively. The addresses y0 and y1 are kept atthe previous values and not updated.

When the bx_to_tr1 command is issued, the error pattern information D isupdated to “Tr”. The row address xC of the defective memory cell iswritten into the address x1. The addresses x0, y0, and y1 are kept atthe previous values and not updated.

Similarly, when the by_to_tr1 command is issued, the error patterninformation D is updated to “Tr”. The column address yC of the defectivememory cell is written into the address y1. The addresses x0, x1, and y0are kept at the previous values and not updated.

When the bx_to_tr2 command is issued, the error pattern information D isupdated to “Tr”. The row address xC of the defective memory cell iswritten into the address x1. The addresses x0, y0, and y1 areoverwritten with the previous values of the addresses x1, y1, and y0,respectively. Similarly, when the by_to_tr2 command is issued, the errorpattern information D is updated to “Tr”. The column address yC of thedefective memory cell is written into the address y1. The addresses x0,x1, and y0 are overwritten with the previous values of the addresses x1,x0, and y1, respectively.

When the tr_to_sncx command or sq_to_bxcx1 command is issued, the errorpattern information D is updated to “Cx”. The row address xC of thedefective memory cell is written into the address x1. The minimum valueymin and the maximum value ymax of the column addresses are written intothe addresses y0 and y1, respectively. The address x0 is kept at theprevious value and not updated. Similarly, when the tr_to_sncy commandor sq_to_bxcy1 command is issued, the error pattern information D isupdated to “Cy”. The column address yC of the defective memory cell iswritten into the address y1. The minimum value xmin and the maximumvalue xmax of the row addresses are written into the addresses x0 andx1, respectively. The address y0 is kept at the previous value and notupdated.

When the tr_to_sq command is issued, the error pattern information D isupdated to “Sq”. The addresses x0, y0, x1, and y1 are kept at theprevious values and not updated.

When the sq_to_bxcx2 command is issued, the error pattern information Dis updated to “Cx”. The row address xC of the defective memory cell iswritten into the address x0. The minimum value ymin and the maximumvalue ymax of the column addresses are written into the addresses y0 andy1, respectively. The address x1 is kept at the previous value and notupdated. Similarly, when the sq_to_bycy2 command is issued, the errorpattern information D is updated to “Cy”. The column address yC of thedefective memory cell is written into the address y0. The minimum valuexmin and the maximum value xmax of the row addresses are written intothe addresses x0 and x1, respectively. The address y1 is kept at theprevious value and not updated.

When the cx_to_cx command is issued, the error pattern information D ismaintained as “Cx”. The minimum value ymin and the maximum value ymax ofthe column addresses are written into the addresses y0 and y1,respectively. The addresses x0 and x1 are kept at the previous valuesand not updated. Similarly, when the cy_to_cy command is issued, theerror pattern information D is maintained as “Cy”. The minimum valuexmin and the maximum value xmax of the row addresses are written intothe addresses x0 and x1, respectively. The addresses y0 and y1 are keptat the previous values and not updated.

Turning to FIG. 19, the field “Da_next” shows error pattern informationD to be written into the defect analysis data FMI<iNull>. The fields“x0a_next”, “y0a_next”, “x1a_next”, “y1a_next”, and “za_next” showaddresses x0, y0, x1, y1, and z to be written into the defect analysisdata FMI<iNull>, respectively. The notations “x0”, “x1”, and “y1”represent the addresses x0, y0, x1, and y1 of the current defectanalysis data FMI<i>, respectively.

Initially, when the tr_to_sncx command is issued, the error patterninformation D is set to “Sn”. The addresses x1 and y0 of the currentdefect analysis data FMI<i> are written into the addresses x0 and y0,respectively. Similarly, when the tr_to_sncy command is issued, theerror pattern information D is set to “Sn”. The addresses x0 and y1 ofthe current defect analysis data FMI<i> are written into the addressesx0 and y0, respectively.

When the sq_to_bxcx1 command is issued, the error pattern information Dis set to “Bx”. The addresses x1, y0, x1, and y1 of the current defectanalysis data FMI<i> are written into the addresses x0, y0, x1, and y1,respectively. Similarly, when the sq_to_bxcx2 command is issued, theerror pattern information D is set to “Bx”. The addresses x0, y0, x0,and y1 of the current defect analysis data FMI<i> are written into theaddresses x0, y0, x1, and y1, respectively.

When the sq_to_bycy1 command is issued, the error pattern information Dis set to “By”. The addresses x0, y1, x1, and y1 of the current defectanalysis data FMI<i> are written into the addresses x0, y0, x1, and y1,respectively. Similarly, when the sq_to_bycy2 command is issued, theerror pattern information D is set to “By”. The addresses x0, y0, x1,and y0 of the current defect analysis data FMI<i> are written into theaddresses x0, y0, x1, and y1, respectively.

The foregoing is the operation of the analysis circuit 143 in thesecondary repair. It is preferred, though not limited in particular,that the foregoing operation of the analysis circuit 143 is implementedby hardware, using logic circuits.

Next, how defect analysis data is updated each time a defective memorycell is detected will be described in conjunction with concreteexamples.

In the present example, the analysis memory 144 is provided with eightpieces of defect analysis data FMI<0> to FMI<7>.

Turning to FIG. 12B, all the pieces of defect analysis data FMI<0> toFMI<7> are reset in the initial state (step S30). When the firstdefective memory cell (XADD=4, YADD=3) is detected, the defect analysisdata FMI<0> is set to the following values:

FMI<0>={Sn,4,3,0,0,0}.  (Step S31)

That is, the defective memory cell is handled as what is called asingle-bit defect (Sn defect) at this point in time.

Next, when the second defective memory cell (XADD=7, YADD=3) isdetected, the defect analysis data FMI<0> is set to the followingvalues:

FMI<0>={By,4,3,7,3,0}.  (Step S32)

That is, the single-bit defect (Sn defect) is updated to a two-bitdefect with the same column addresses (By defect).

When the third defective memory cell (XADD=B, YADD=3) is detected, thedefect analysis data FMI<0> is set to the following values:

FMI<0>={Cy,4,3,B,3,0}.  (Step S33)

That is, the two-bit defect (By defect) is updated to a line defect inthe column direction (Cy defect).

When the fourth defective memory cell (XADD=D, YADD=3) is detected, thedefect analysis data FMI<0> is set to the following values:

FMI<0>={Cy,4,3,D,3,0}.  (Step S34)

When the fifth defective memory cell (XADD=E, YADD=3) is detected, thedefect analysis data FMI<0> is set to the following values:

FMI<0>={Cy,4,3,E,3,0}.  (Step S35)

In such a case, the defect remains a line defect in the column direction(Cy defect) but with updated address information.

When the sixth defective memory cell (XADD=6, YADD=6) is detected, a newpiece of defect analysis data FMI<1> is used. The defect analysis dataFMI<1> is set to the following values:

FMI<1>={Sn,6,6,0,0,0}.  (Step S36)

That is, a single-bit defect (Sn defect) is added to the line defect inthe column direction (Cy defect).

When the seventh defective memory cell (XADD=6, YADD=8) is detected, thedefect analysis data FMI<1> is set to the following values:

FMI<1>={Bx,6,6,6,8,0}.  (Step S37)

That is, the single-bit defect (Sn defect) is updated to a two-bitdefect with the same row addresses (Bx defect).

When the eighth defective memory cell (XADD=6, YADD=9) is detected, thedefect analysis data FMI<1> is set to the following values:

FMI<1>={Cx,6,6,6,9,0}.  (Step S38)

That is, the two-bit defect (Bx defect) is updated to a line defect inthe row direction (Cx defect).

When the ninth defective memory cell (XADD=6, YADD=C) is detected, thedefect analysis data FMI<1> is set to the following values:

FMI<1>={Cx,6,6,6,C,0}.  (Step S39)

In such a case, the defect remains a line defect in the row direction(Cx defect) but with updated address information.

As a result of the foregoing process, the following two pieces of defectanalysis data are stored in the analysis memory 144:

FMI<0>={Cy,4,3,E,3,0},

and

FMI<1>={Cx,6,6,6,C,0}.

In such a case, a word line of XADD=6 and a bit line of YADD=3 areconsidered to be a defective word line and a defective bit line, whichare replaced with a redundant word line and a redundant bit line,respectively. In other words, in step S9 shown in FIG. 5, theinformation on XADD=6 and YADD=3 is written into the electrical fusecircuit 142.

Turing to FIGS. 13A and 13B, also in the second concrete example, theanalysis memory 144 is provided with eight pieces of defect analysisdata FMI<0> to FMI<7>.

As shown in FIG. 13B, all the pieces of defect analysis data FMI<0> toFMI<7> are reset in the initial state (step S40). When the firstdefective memory cell (XADD=1, YADD=1) is detected, the defect analysisdata FMI<0> is set to the following values:

FMI<0>={Sn,1,1,0,0,0}.  (Step S41)

That is, the defective memory cell is handled as what is called asingle-bit defect (Sn defect) at this point in time.

Next, when the second defective memory cell (XADD=4, YADD=4) isdetected, a new piece of defect analysis data FMI<1> is used. The defectanalysis data FMI<1> is set to the following values:

FMI<1>={Sn,4,4,0,0,0}.  (Step S42)

That is, another single-bit defect (Sn defect) is added to thesingle-bit defect (Sn defect).

When the third defective memory cell (XADD=7, YADD=4) is detected, thedefect analysis data FMI<1> is set to the following values:

FMI<1>={By,4,4,7,4,0}.  (Step S43)

That is, one of the single-bit defects (Sn defects) is updated to atwo-bit defect with the same column addresses (By defect).

When the fourth defective memory cell (XADD=4, YADD=7) is detected, thedefect analysis data FMI<1> is set to the following values:

FMI<1>={Tr,4,4,7,7,0}.  (Step S44)

That is, the two-bit defect (Bx defect) is updated to an L-shapedthree-bit defect (Tr defect).

When the fifth defective memory cell (XADD=7, YADD=7) is detected, thedefect analysis data FMI<1> is set to the following values:

FMI<1>={Sq,4,4,7,7,0}.  (Step S45)

That is, the L-shaped three-bit defect (Tr defect) is updated to arectangular four-bit defect (Sq defect).

When the sixth defective memory cell (XADD=7, YADD=B) is detected, a newpiece of defect analysis data FMI<2> is used. The reorder flag ReOrderis set to sort the pieces of defect analysis data, which are set asfollows:

FMI<0>={Cx,7,4,7,B,0},

FMI<1>={Sn,1,1,0,0,0},

and

FMI<2>={Bx,4,4,4,7,0}.  (Step S46)

That is, the rectangular four-bit defect (Sq defect) is divided into atwo-bit defect (Bx defect) and a line defect in the row direction (Cxdefect).

When the seventh defective memory cell (XADD=7, YADD=1) is detected, thedefect analysis data FMI<0> is set to the following values:

FMI<0>={Cx,7,1,7,B,0}.  (Step S47)

In such a case, the defect remains a line defect in the row direction(Cx defect) but with updated address information.

When the eighth defective memory cell (XADD=4, YADD=D) is detected, thereorder flag ReOrder is set to sort the pieces of defect analysis data,which are set as follows:

FMI<0>={Cx,4,4,4,D,0},

FMI<1>={Cx,7,1,7,B,0},

and

FMI<2>={Sn,1,1,0,0,0}.  (Step S48)

That is, the two-bit defect (Bx defect) is updated to a line defect inthe row direction (Cx defect).

When the ninth defective memory cell (XADD=4, YADD=1) is detected, thedefect analysis data FMI<0> is set to the following values:

FMI<0>={Cx,4,1,4,D,0}.  (Step S49)

In such a case, the defect remains a line defect in the row direction(Cx defect) but with updated address information.

As a result of the foregoing process, the following three pieces ofdefect analysis data are stored in the analysis memory 144:

FMI<0>={Cx,4,1,4,D,0},

FMI<1>={Cx,7,1,7,B,0},

and

FMI<2>={Sn,1,1,0,0,0}.

In such a case, word lines of XADD=4 and 7 are considered as defectiveword lines, and either a word line of XADD=1 or a bit line of YADD=1 asa defective word line or defective bit line. Such defective lines arereplaced with respective redundant word lines or the like. In otherwords, in step S9 shown in FIG. 5, the information on XADD=1, 4, and 7is written into the electrical fuse circuit 142.

As has been described above, according to the present embodiment, errorpattern information and error address information are updated each timea defective memory cell is detected in secondary repair after packaging.This significantly reduces the capacity of the work memory needed foranalysis. Since the analysis memory 144 can be implemented inside thesemiconductor device 100, the external tester for use in secondaryrepair need not include an analysis memory.

In particular, when defective memory cells are found in variousaddresses at random as in the second concrete example shown in FIG. 13,the method described in Japanese Patent Application Laid-Open No.2001-52497 needs a work area or analysis memory of high capacity. Incontrast, according to the method of the present embodiment, only arelatively small work area is used even when defective memory cells arefound in various addresses at random. This makes it possible to designthe analysis memory 144 with a small storage capacity.

Turning to FIG. 20, initially, an operation test is performed by usingthe external tester 200 (step S90). The operation test is performed byaccessing the semiconductor device 100 at the same speed as theoperating speed in actual use. That is, a write operation is performedat the maximum design speed, followed by a read operation at the maximumspeed. The external tester 200 compares the read data DQ resulting fromthe operation test with expected values (i.e., write data) to evaluatewhether there is any defective address (step S91).

If there is no defective address (step S91: NO), the processing ends. Onthe other hand, if there is any defective address (step S91: YES), theexternal tester 200 issues a test command so that the semiconductordevice 100 enters a test mode for tertiary repair (step S92). Thischanges the mode select signal PT supplied to the analysis circuit 143to a high level, and the analysis circuit 143 enters an operation modein which it can accept defective addresses based on the data mask signalDM.

Next, the external tester 200 changes the data mask signal DM to a highlevel (step S93), and inputs the detected defective addresses into thesemiconductor device 100 (step S95). The addresses are input by the samemethod as in a read access. A bank address BA and a row address XADD areinput in synchronization with an active command (ACT). A column addressYADD is input in synchronization with a read command (READ). Suchprocessing is performed on all the defective addresses found (step S96:NO) and then a write command for electrical fuses is issued to thesemiconductor device 100 (step S97). Consequently, the defectiveaddresses that are stored into the analysis memory 144 through theanalysis circuit 143 are written into the electrical fuse circuit 142.

This completes the tertiary repair. As described above, tertiary repairis performed by using a high-speed external tester 200 after thecompletion of primary repair and secondary repair. It is thereforepossible to find defects that occur only under fast access, and relieveaddresses where such defects exist. As mentioned previously, very fewdefective addresses are found by tertiary repair. The external tester200 therefore need not include a high-capacity analysis memory.

Turning to FIG. 21, when tertiary repair is performed on a plurality ofsemiconductor devices 100 in parallel, the address terminals 112,command terminals 120, control terminals 121, and clock terminals 122 ofthe semiconductor devices 100 are connected to the external tester 200in common. The data system terminals 131 of the semiconductor devices100 are connected to the external tester 200 by using respectivedifferent wirings. When an operation test is performed in such a state,the semiconductor devices 100 make the same operation. Since thesemiconductor devices 100 have respective different defective addressesif any, the semiconductor devices 100 output erroneous read data DQ eachtime a defective address is accessed. The read data DQ is supplied fromthe semiconductor devices 100 to the external tester 200 through therespective different wirings. The external tester 200 can thus detectdefective addresses with respect to each of the semiconductor devices100.

Turning to FIG. 22, initially, a plurality of semiconductor devices 100to be subjected to tertiary repair and the external tester 200 areconnected as shown in FIG. 21, and an operation test is performed inparallel (step S90). The operation test is performed at the maximumdesign speed. The external tester 200 evaluates whether there is anydefective semiconductor device 100 (step S91 a).

If there is no defective semiconductor device 100 (step S91 a: NO), theprocessing ends. On the other hand, if there is any defectivesemiconductor device 100 (step S91 a: YES), the external tester 200issues a test command so that all the semiconductor devices 100 enter atest mode for tertiary repair (step S92).

Next, the external tester 200 changes the data mask signal DM of one ofdefective semiconductor devices 100 to a high level (step S93 a), andoutputs a detected defective address (step S95). The defective addressis input to all the semiconductor devices 100, but is valid only to thesemiconductor device 100 in which the data mask signal DM is at a highlevel. The defective address is ignored by the other semiconductordevices 100 where the data mask signal DM is at a low level. Suchprocessing is performed on all defective addresses found in thesemiconductor device 100 (step S96: NO) and then a write command forelectrical fuses is issued (step S97). Consequently, the defectiveaddresses that are stored into the analysis memory 144 through theanalysis circuit 143 are written into the electrical fuse circuit 142.

The foregoing processing is performed on each of all the semiconductordevices 100 that are found to be defective. When the processing on allthe semiconductor devices 100 is completed (step S99: NO), the series oftertiary repair is completed. As described above, according to thepresent embodiment, the data mask signal DM is used for deviceselection. This makes it possible to perform tertiary repair on aplurality of semiconductor devices 100 in parallel.

Next, a preferred second embodiment of the present invention will bedescribed. The present embodiment deals with an example where thepresent invention is applied to a stacked semiconductor device in whicha plurality of semiconductor chips are stacked and packaged in a singlepackage.

Turning to FIG. 23, the semiconductor device 10 according to thisembodiment has the structure where 8 core chips CC0 to CC7 and aninterface chip IF are stacked on an interposer IP. The core chips CC0 toCC7 have the same function and structure as one another. It is worthnoting that the uppermost core chip CC0 may have a different structurefrom the other core chips CC1 to CC7. For example, the uppermost corechip CC0 may be thicker than the remaining core chips CC1 to CC7. Thecore chips CC0 to CC7 are manufactured using the same manufacture maskwhereas the interface chip IF is manufactured using a manufacture maskdifferent from that of the core chips CC0 to CC7. The core chips CC0 toCC7 and the interface chip IF are semiconductor chips using a siliconsubstrate and are electrically connected to adjacent chips in a verticaldirection through plural through silicon vias TSV penetrating thesilicon substrate. The through silicon vias may be referred to aspenetration electrodes. The uppermost core chip CC0 may not have thethrough silicon via TSV. Meanwhile, the interposer IP is a circuit boardthat is made of a resin, and plural external terminals (solder balls) SBare formed in a back surface IPb of the interposer IP.

The core chips CC0 to CC7 each are a semiconductor chip that includescircuit blocks of an ordinary stand-alone SDRAM (Synchronous DynamicRandom Access Memory), excluding an external interface so-called frontend section. In other words, the core chips CC0 to CC7 are memory chipsin which only the circuit blocks belonging to back end sections areintegrated. Examples of circuit blocks included in a front end sectioninclude a parallel-serial conversion circuit that performsparallel-serial conversion of input/output data between a memory cellarray and data input/output terminals, and a DLL (Delay-Locked Loop)circuit that controls data input/output timing. Details will be givenlater.

On the other hand, the interface chip IF is a semiconductor chip inwhich only the front end unit in circuit blocks of an ordinarystand-alone SDRAM is integrated. The interface chip IF functions as acommon front end unit for the eight core chips CC0 to CC7. Accordingly,all external accesses are performed through the interface chip IF andinputs/outputs of data are also performed through the interface chip IF.In this embodiment, the interface chip IF is disposed between theinterposer IP and the core chips CC0 to CC7. However, the position ofthe interface chip IF is not restricted in particular, and the interfacechip IF may be disposed on the core chips CC0 to CC7 and may be disposedon the back surface IPb of the interposer IP. When the interface chip IFis disposed on the core chips CC0 to CC7 in a face-down manner or isdisposed on the back surface IPb of the interposer IP in a face-upmanner, the through silicon via TSV does not need to be provided in theinterface chip IF. The interface chip IF may be disposed to beinterposed between the two interposers IP.

The interposer IP functions as a rewiring substrate to increase anelectrode pitch and secures mechanical strength of the semiconductordevice 10. That is, an electrode 91 that is formed on a top surface IPaof the interposer IP is drawn to the back surface IPb via a through-holeelectrode 92 and the pitch of the external terminals SB is enlarged bythe rewiring layer 93 provided on the back surface IPb. In FIG. 23, onlythe two external terminals SB are shown. In actuality, however, three ormore external terminals are provided. The layout of the externalterminals SB is the same as that of the DDR3-type SDRAM that isdetermined by the regulation. Accordingly, the semiconductor memorydevice can be treated as one DDR3-type SDRAM from the externalcontroller.

As shown in FIG. 23, a top surface of the uppermost core chip CC0 iscovered by an NCF (Non-Conductive Film) 94 and a lead frame 95. Gapsbetween the core chips CC0 to CC7 and the interface chip IF are filledwith an underfill 96 and surrounding portions of the gaps are covered bya sealing resin 97. Thereby, the individual chips are physicallyprotected.

When most of the through silicon vias TSV provided in the core chips CC0to CC7 are two-dimensionally viewed from a lamination direction, thatis, viewed from an arrow A shown in FIG. 23, the through silicon viasTSV are short-circuited from the through silicon vias TSV of otherlayers provided at the same position. That is, as shown in FIG. 24A, thevertically disposed through silicon vias TSV1 that are provided at thesame position in plain view are short-circuited, and one wiring line isconfigured by the through silicon via TSV1. The through silicon via TSV1that are provided in the core chips CC0 to CC7 are connected to internalcircuits 4 in the core chips, respectively. Accordingly, input signals(command signal, address signal, etc.) that are supplied from theinterface chip IF to the through silicon vias TSV1 shown in FIG. 24A arecommonly input to the internal circuits 4 of the core chips CC0 to CC7.Output signals (data etc.) that are supplied from the core chips CC0 toCC7 to the through silicon via TSV1 are wired-ORed and input to theinterface chip IF.

Meanwhile, as shown in FIG. 24B, the a part of through silicon vias TSVare not directly connected to the through silicon via TSV2 of otherlayers provided at the same position in plain view but are connected tothe through silicon via TSV2 of other layers through the internalcircuits 5 provided in the core chips CC0 to CC7. That is, the internalcircuits 5 that are provided in the core chips CC0 to CC7 arecascade-connected through the through silicon via TSV2. This kind ofthrough silicon via TSV2 is used to sequentially transmit predeterminedinformation to the internal circuits 5 provided in the core chips CC0 toCC7. As this information, layer address information to be describedbelow is exemplified.

Another through silicon via TSV group is short-circuited from thethrough silicon vias TSV of other layer provided at the differentposition in plain view, as shown in FIG. 24C. With respect to this kindof through silicon via TSV group 3, internal circuits 6 of the corechips CC0 to CC7 are connected to the through silicon via TSV3a providedat the predetermined position P in plain view. Thereby, information canbe selectively input to the internal circuits 6 provided in the corechips. As this information, defective chip information to be describedbelow is exemplified.

As such, as types of the Through silicon vias TSV provided in the corechips CC0 to CC7, three types (through silicon via TSV1 to throughsilicon via TSV3) shown in FIGS. 24A to 24C exist. As described above,most of the Through silicon vias TSV are of a type shown in FIG. 24A,and an address signal, a command signal, and a clock signal are suppliedfrom the interface chip IF to the core chips CC0 to CC7, through thethrough silicon via TSV1 of the type shown in FIG. 24A. Read data andwrite data are input to and output from the interface chip IF throughthe through silicon via TSV1 of the type shown in FIG. 24A. Meanwhile,the through silicon via TSV2 and through silicon via TSV3 of the typesshown in FIGS. 24B and 24C are used to provide individual information tothe core chips CC0 to CC7 having the same structure.

Turning to FIG. 25, the through silicon via TSV1 is provided topenetrate a silicon substrate 180 and an interlayer insulating film 181provided on a surface of the silicon substrate 180. Around the throughsilicon via TSV1, an insulating ring 182 is provided. Thereby, thethrough silicon via TSV1 and a transistor region are insulated from eachother. In an example shown in FIG. 25, the insulating ring 182 isprovided double. Thereby, capacitance between the through silicon viaTSV1 and the silicon substrate 180 is reduced.

An end 183 of the through silicon via TSV1 at the back surface of thesilicon substrate 180 is covered by a back surface bump 184. The backsurface bump 184 is an electrode that contacts a surface bump 185provided in a core chip of a lower layer. The surface bump 185 isconnected to an end 186 of the through silicon via TSV1, through pluralpads P0 to P3 provided in wiring layers L0 to L3 and plural through-holeelectrodes TH1 to TH3 connecting the pads to each other. Thereby, thesurface bump 185 and the back surface bump 184 that are provided at thesame position in plain view are short-circuited. Connection withinternal circuits (not shown in the drawings) is performed throughinternal wiring lines (not shown in the drawings) drawn from the pads P0to P3 provided in the wiring layers L0 to L3.

Turning to FIG. 26, the through silicon via TSV2 differs from thethrough silicon via TSV1 shown in FIG. 25 in the omission of thethrough-hole electrodes TH2 which directly connect the pad P1 and thepad P2 lying in the same planar position. The pad P1 is connected to,for example, the output node of an internal circuit 5 shown in FIG. 24B.The pad P2 is connected to, for example, the input node of the internalcircuit 5 shown in FIG. 28B. The internal circuits 5 arranged in thecore chips CC0 to CC7 are thus cascaded through the intervention ofthrough silicon vias TSV2.

Turning to FIG. 27, the through silicon vias TSV3 are configured not sothat the pads P1 and P2 formed in the same planar positions areconnected by through-hole electrodes TH2, but so that pads P1 and P2formed in different planar positions are connected by through-holeelectrodes TH2. While FIG. 27 shows only three through silicon viasTSV3, there are provided through silicon vias TSV3 as many as the numberof core chips CC0 to CC7 (eight) per signal. The eight through siliconvias TSV3 are cyclically connected as shown in FIG. 28. FIG. 28 showssurface bumps 185 in solid lines and rear bumps 184 in broken lines. Asshown in FIG. 28, the cyclic connection of the through silicon vias TSV3makes it possible to supply individual data from the interface chip IFto the respective core chips CC0 to CC7 with the core chips CC0 to CC7identical in circuit configuration. For example, if internal circuit 6are connected to the positions of the rear bumps 184-7, signals suppliedfrom the interface chip IF to the rear bumps 184-0 to 184-7 of thelowermost core chip CC7 are selectively supplied to the internalcircuits 6 of the core chips CC0 to CC7, respectively.

Turning to FIG. 29, the external terminals that are provided in theinterposer IP include clock terminals 11 a and 11 b, an clock enableterminal 11 c, command terminals 12 a to 12 f, an address terminal 13 ato 13 c, a data input/output terminal 14, data strobe terminals 15 a and15 b, a calibration terminal 16, power supply terminals 17 a and 17 b,and a data mask terminal 18. All of the external terminals other thanthe power supply terminals 17 a and 17 b are connected to the interfacechip IF and are not directly connected to the core chips CC0 to CC7.

First, a connection relationship between the external terminals and theinterface chip IF and the circuit configuration of the interface chip IFwill be described.

The clock terminals 11 a and 11 b are supplied with external clocksignals CK and /CK, respectively, and the clock enable terminal 11 c issupplied with a clock enable signal CKE. The external clock signals CKand /CK and the clock enable signal CKE are supplied to a clockgenerating circuit 21 provided in the interface chip IF. A signal where“/” is added to a head of a signal name in this specification indicatesan inversion signal of a corresponding signal or a low-active signal.Accordingly, the external clock signals CK and /CK are complementarysignals. The clock generating circuit 21 generates an internal clocksignal ICLK, and the generated internal clock signal ICLK is supplied tovarious circuit blocks in the interface chip IF and is commonly suppliedto the core chips CC0 to CC7 through the through silicon vias TSV.

A DLL circuit 22 is included in the interface chip IF and aninput/output clock signal LCLK is generated by the DLL circuit 22. Theinput/output clock signal LCLK is supplied to an input/output buffercircuit 23 included in the interface chip IF. A DLL function is used tocontrol the front end unit by using the signal LCLK synchronized with asignal of the external device, when the semiconductor device 10communicates with the external device. Accordingly, DLL function is notneeded for the core chips CC0 to CC7 as the back end.

The command terminals 12 a to 12 f are supplied with a chip selectsignal /CS, a row-address strobe signal /RAS, a column address strobesignal /CAS, a write enable signal /WE, an on-die termination signalODT, and a reset signal /RESET. These command signals are supplied to acommand input buffer 31 that is provided in the interface chip IF. Thecommand signals supplied to the command input buffer 31 are furthersupplied to a control logic 32. The control logic 32 includes a latencycontroller 32 a and a command decoder 32 b. The control logic 32 is acircuit that holds, decodes, and counts the command signals insynchronization with the internal clock ICLK and generates variousinternal commands ICMD. The generated internal command ICMD is suppliedto the various circuit blocks in the interface chip IF and is commonlysupplied to the core chips CC0 to CC7 through a TSV buffer 34 and thethrough silicon vias TSV1.

The address terminal 13 a is a terminal to which a bank address BA0 toBA2 is supplied. The address terminal 13 b is a terminal to which anaddress signal A0 to A(N−3) is supplied. The address terminal 13C is aterminal to which an address signal AN to A(N−2) is supplied. Thesupplied address signals A0 to AN (A15) and BA0 to BA2 are supplied toan address input buffer 41 which is arranged in the interface chip IF.The output of the address input buffer 41 is supplied to the controllogic 32 and a layer address buffer 48. The layer address buffer 48functions to supply a layer address (layer information) EXA to the corechips CC0 to CC7 in common through the through silicon vias TSV1. Whenin mode register setting, the address signal A0 to AN (A15) supplied tothe control logic 32 is supplied to a mode register 42 which is arrangedin the interface chip IF. The bank address BA0 to BA2 is decoded by thecontrol logic 32, and the resulting bank select signal is supplied to aFIFO circuit 25. The reason is that bank selection on write data isperformed inside the interface chip IF.

The data input/output terminal 14 is used to input/output read data orwrite data DQ0 to DQ7. The data strobe terminals 15 a and 15 b areterminals that are used to input/output strobe signals DQS and /DQS. Thedata mask terminal 18 is a terminal to which a data mask signal DM issupplied. The data input/output terminal 14, the data strobe terminals15 a and 15 b, and the data mask terminal 18 are connected to theinput/output buffer circuit 23 provided in the interface chip IF. Thedata mask signal DM supplied through the data mask terminal 18 is alsosupplied to an analysis circuit 82 a. The input/output buffer circuit 23includes an input buffer IB and an output buffer OB, and inputs/outputsthe read data or the write data DQ0 to DQ7 and the strobe signals DQSand /DQS in synchronization with the input/output clock signal LCLKsupplied from the DLL circuit 22. If an internal on-die terminationsignal IODT is supplied from the control logic 32, the input/outputbuffer circuit 23 causes the output buffer OB to function as atermination resistor. An impedance code DRZQ is supplied from thecalibration circuit 24 to the input/output buffer circuit 23. Thereby,impedance of the output buffer OB is designated.

The calibration circuit 24 includes a replica buffer RB that has thesame circuit configuration as the output buffer OB. If the calibrationsignal ZQC is supplied from the control logic 32, the calibrationcircuit 24 refers to a resistance value of an external resistor (notshown in the drawings) connected to the calibration terminal 16 andperforms a calibration operation. The calibration operation is anoperation for matching the impedance of the replica buffer RB with theresistance value of the external resistor, and the obtained impedancecode DRZQ is supplied to the input/output buffer circuit 23. Thereby,the impedance of the output buffer OB is adjusted to a desired value.

The input/output buffer circuit 23 is connected to a FIFO circuit 25.The FIFO circuit 25 includes a FIFO circuit unit (not shown in thedrawings) that realizes a FIFO function which operates by latencycontrol realizing the well-known DDR function and a multiplexer (notshown in the drawings). The input/output buffer circuit 23 convertsparallel read data, which is supplied from the core chips CC0 to CC7,into serial read data, and converts serial write data, which is suppliedfrom the input/output buffer, into parallel write data. Accordingly, thedata latch circuit 25 and the input/output buffer circuit 23 areconnected in serial and the FIFO circuit 25 and the core chips CC0 toCC7 are connected in parallel. Parallel write data output from the FIFOcircuit 25 is supplied to the core chips CC0 to CC7 through a TSV buffer26. Parallel read data output from the core chips CC0 to CC7 is suppliedto the FIFO circuit 25 through the TSV buffer 26. In this embodiment,each of the core chips CC0 to CC7 is the back end unit of the DDR3-typeSDRAM and a prefetch number is 8 bits. The FIFO circuit 25 and eachbanks of the core chips CC0 to CC7 are connected respectively, and thenumber of banks that are included in each of the core chips CC0 to CC7is 8. Accordingly, connection of the FIFO circuit 25 and the core chipsCC0 to CC7 becomes 64 bits (8 bits×8 banks) for each DQ.

Parallel data, not converted into serial data, is basically transferredbetween the FIFO circuit 25 and the core chips CC0 to CC7. That is, in acommon SDRAM (in the SDRAM, a front end unit and a back end unit areconstructed in one chip), between the outside of the chip and the SDRAM,data is input/output in serial (that is, the number of data input/outputterminals is one for each DQ). However, in the core chips CC0 to CC7, aninput/output of data between the interface chip IF and the core chips isperformed in parallel. This point is the important difference betweenthe common SDRAM and the core chips CC0 to CC7. However, all of theprefetched parallel data do not need to be input/output using thedifferent through silicon vias TSV, and partial parallel/serialconversion may be performed in the core chips CC0 to CC7 and the numberof through silicon vias TSV that are needed for each DQ may be reduced.For example, all of data of 64 bits for each DQ do not need to beinput/output using the different through silicon vias TSV, and 2-bitparallel/serial conversion may be performed in the core chips CC0 to CC7and the number of through silicon vias TSV that are needed for each DQmay be reduced to ½ (32).

To the FIFO circuit 25, a function for enabling a test in an interfacechip unit is added. The interface chip does not have the back end unit.For this reason, the interface chip cannot be operated as a single chipin principle. However, if the interface chip IF never operates as thesingle chip, an operation test of the interface chip IF in a wafer statemay not be performed. This means that the semiconductor memory device 10cannot be tested in case an assembly process of the interface chip andthe plural core chips is not executed, and the interface chip is testedby testing the semiconductor memory device 10. In this case, when adefect that cannot be recovered exists in the interface chip, the entiresemiconductor memory device 10 is not available. In consideration ofthis point, in this embodiment, a portion of a pseudo back end unit fora test is provided in the FIFO circuit 25, and a simple memory functionis enabled at the time of a test.

The power supply terminals 17 a and 17 b are terminals to which powersupply potentials VDD and VSS are supplied, respectively. The powersupply terminals 17 a and 17 b are connected to a power-on detectingcircuit 43 provided in the interface chip IF and are also connected tothe core chips CC0 to CC7 through the through silicon vias TSV1. Thepower-on detecting circuit 43 detects the supply of power. On detectingthe supply of power, the power-on detecting circuit 43 activates a layeraddress control circuit 45 on the interface chip IF.

The layer address control circuit 45 changes a layer address due to theI/O configuration of the semiconductor device 10 according to thepresent embodiment. As described above, the semiconductor device 10includes 8 data input/output terminals 14. Thereby, a maximum I/O numbercan be set to 8 bits (DQ0 to DQ7). However, the I/O number is not fixedto 8 bits and, for example, may be set to 4 bits (DQ0 to DQ3). Theaddress allocation is changed according to the I/O number and the layeraddress is also changed. The layer address control circuit 45 changesthe address allocation according to the I/O number and is commonlyconnected to the core chips CC0 to CC7 through the Through silicon viasTSV1.

The interface chip IF is also provided with a layer address settingcircuit 44. The layer address setting circuit 44 is connected to thecore chips CC0 to CC7 through the through silicon vias TSV2. The layeraddress setting circuit 44 is cascade-connected to the layer addressgenerating circuit 46 of the core chips CC0 to CC7 using the throughsilicon via TSV2 of the type shown in FIG. 24B, and reads out the layeraddresses set to the core chips CC0 to CC7 at testing.

The interface chip IF is also provided with a defective chip informationholding circuit 33. When a defective core chip that does not normallyoperates is discovered after an assembly, the defective chip informationholding circuit 33 holds its chip number. The defective chip informationholding circuit 33 is connected to the core chips CC0 to CC7 through thethrough silicon vias TSV3. The defective chip information holdingcircuit 33 is connected to the core chips CC0 to CC7 while beingshifted, using the through silicon via TSV3 of the type shown in FIG.24C.

The interface chip IF further includes an electrical fuse circuit 83.The electrical fuse circuit 83 is a circuit that stores information thatis needed to replace defects found after assembly with redundancycircuits. The information to be stored in the electrical fuse circuit 83includes at least information on defects of the through silicon vias TSVand information on defects of the memory cells in the core chips CC0 toCC7. The TSV buffers 26 and 34 can replace the defective through siliconvias TSV with other through silicon vias TSV for repair. Since suchrepair is not directly related to the gist of the present invention,detailed description thereof will thus be omitted. The defective throughsilicon vias TSV are detected by using a DFT circuit 81, and programmedinto the electrical fuse circuit 83.

The electrical fuse circuit 83 stores row addresses that represent wordlines to be replaced or column addresses that represent bit lines to bereplaced. Redundant word lines or redundant bit lines included in thecorresponding core chips CC0 to CC7 are used as replacing redundant wordlines or redundant bit lines.

The information stored in the electrical fuse circuit 83 includesinformation on defective addresses of memory cells, which is seriallyconverted into serial data ALD by a serializer 84 before transferred tothe core chips CC0 to CC7 via through silicon vias TSV. As shown in FIG.29, defective addresses are transferred by using a plurality of throughsilicon vias TSV in parallel so as to avoid transfer defect due todefects of the through silicon vias TSV themselves. Other signals thatuse irreplaceable through silicon vias TSV, such as the layer addressEXA and a determination signal P/F to be described later, also use aplurality of through silicon vias TSV in parallel.

The electrical fuse circuit 83 is programmed by the analysis circuit 82a and an analysis memory 82 b. The analysis circuit 82 a, the analysismemory 82 b and the fuse select circuit 82C correspond to the analysiscircuit 143, the analysis memory 144 and the fuse select circuit 146shown in FIG. 1, respectively. The analysis circuit 82 a is activated bya signal FENT which is the output of a DFT circuit 37. The analysiscircuit 82 a analyzes the pattern of occurrence of defective memorycells based on addresses supplied from the control logic 32 and thedetermination signal P/F supplied from the core chips CC0 to CC7 insecondary repair (the mode select signal PT=low). The analysis isintended to identify a pattern that allows most efficient replacementwhen replacing defective memory cells in units of word lines or bitlines. This means that the addresses stored in the electrical fusecircuit 83 are not in units of memory cells but in units of word linesor bit lines. The replacement in units of word lines or bit lines isperformed during manufacturing when the core chips CC0 to CC7 are in awafer state. The electrical fuse circuit 83 uses redundant word lines orbit lines that remain unused by the replacement in the wafer state. Theanalysis circuit 82 a is thus a fail memory repair analyzer. In tertiaryrepair (the mode select signal PT=high), the analysis circuit 82 aoutputs to the analysis memory 82 b the address that is supplied fromthe control logic 32 in the period when the data mask signal DM is at ahigh level. The mode select signal PT is output from the DFT circuit 37.

The information programmed in the electrical fuse circuit 83 is read byusing a load circuit 85. The load circuit 85 reads the informationprogrammed in the electrical fuse circuit 83 and generates timingsignals ALFL and ALCK, thereby functioning to synchronize the serializer84 with the core chips CC0 to CC7.

The above description is the outline of the connection relationshipbetween the external terminals and the interface chip IF and the circuitconfiguration of the interface chip IF. Next, the circuit configurationof the core chips CC0 to CC7 will be described.

As shown in FIG. 29, memory cell arrays 50 that are included in the corechips CC0 to CC7 having the back end function are divided into eightbanks. A bank is a unit that can individually receive a command. Thatis, the individual banks can be independently and nonexclusivelycontrolled. From the outside of the semiconductor device 10 (an outsidecontroller which controls the semiconductor device 10), each back can beindependently accessed. For example, a part of the memory cell array 50belonging to the bank 1 and another part of the memory cell array 50belonging to the bank 2 are controlled nonexclusively. That is, wordlines WL and bit lines BL corresponding to each banks respectively areindependently accessed at same period by different commands one another.For example, while the bank 1 is maintained to be active (the word linesand the bit lines are controlled to be active), the bank 2 can becontrolled to be active. However, the external terminals (for example,plural control terminals and plural I/O terminals) of the semiconductormemory device 10 are shared. In the memory cell array 50, the pluralword lines WL and the plural bit lines BL intersect each other, andmemory cells MC are disposed at intersections thereof (in FIG. 29, onlyone word line WL, one bit line BL, and one memory cell MC are shown).

The memory cell array 50 includes a row redundancy array 50 a and acolumn redundancy array 50 b. The row redundancy array 50 a includesredundant cells RMC that are connected to a plurality of redundant wordlines RWL. The column redundancy array 50 b includes redundant cells RMCthat are connected to a plurality of redundant bit lines RBL. The rowredundancy array 50 a is accessed as an alternative if anaccess-requested memory cell belongs to a defective word line. Thecolumn redundancy array 50 b is accessed as an alternative if anaccess-requested memory cell belongs to a defective bit line. Suchalternative accesses are made when an access is requested to theaddresses that are stored in the foregoing electrical fuse circuit 83 oroptical fuse circuits 55 and 57 to be described later.

The word lines WL are selected by a row decoder 51. The bit lines BL areconnected to corresponding sense amplifiers SA in a sense circuit 53.The sense amplifiers SA are selected by a column decoder 52.

The row decoder 51 is controlled by a row address supplied from a rowcontrol circuit 61. The row control circuit 61 includes an addressbuffer 61 a that receives a row address supplied from the interface chipIF through the through silicon via TSV, and the row address that isbuffered by the address buffer 61 a is supplied to the row decoder 51.The address signal that is supplied through the through silicon via TSVis supplied to the row control circuit through the input buffer B1through a TSV receiver and a control logic circuit 63. The row controlcircuit 61 also includes a refresh counter 61 b. When an internalrefresh command is issued by the control logic circuit 63, a row addressthat is indicated by the refresh counter 61 b is supplied to the rowdecoder 51.

The row decoder 51 includes a not-shown address comparison circuit,which compares the row address supplied from the row control circuit 61with addresses retained in a defective address latch circuit 56. Thedefective address latch circuit 56 is a circuit that latches defectiverow addresses read from the optical fuse circuit 55. The defectiveaddress latch circuit 56 includes a circuit that latches the defectiverow addresses read from the optical fuse circuit 55, as well as acircuit that latches defective row addresses read from the electricalfuse circuit 83. If the comparison by the row decoder 51 shows a matchof the addresses, a redundant word line included in the row redundancyarray 50 a is accessed instead of the word line that is designated bythe row address. If the addresses do not match, the word line designatedby the row address is simply accessed.

The optical fuse circuit 55 includes a plurality of fuse sets. The fusesets correspond to the respective plurality of redundant word lines inthe row redundancy array 50 a. That is, if a fuse set is programmed witha row address and an access to that row address is requested, then theredundant word line associated with that fuse set is accessed. Some ofthe fuse sets included in the optical fuse circuit 55 correspond tothose included in the electrical fuse circuit 83 on a one-to-one basis.Consequently, redundant word lines that are specified as replacing wordlines by some of the fuse sets included in the optical fuse circuit 55can also be specified as replacing word lines by fuse sets included inthe electrical fuse circuit 83. However, the optical fuse circuit 55 andthe electrical fuse circuit 83 will not conflict with each other. Aredundant word line is used as a replacing word line by either one of afuse set included in the optical fuse circuit 55 and a fuse set includedin the electrical fuse circuit 83.

The column decoder 52 is controlled by a column address supplied from acolumn control circuit 62. The column control circuit 62 includes anaddress buffer 62 a that receives a column address supplied from theinterface chip IF through the through silicon vias TSV. The columnaddress buffered in the address buffer 62 a is supplied to the columndecoder 52. The column control circuit 62 also includes a burst counter62 b that counts the burst length.

The column decoder 52 includes a not-shown address comparison circuit,which compares the column address supplied from the column controlcircuit 62 with addresses retained in a defective address latch circuit58. The defective address latch circuit 58 is a circuit that latchesdefective column addresses read from the optical fuse circuit 57. Thedefective address latch circuit 58 includes a circuit that latches thedefective column addresses read from the optical fuse circuit 57, aswell as a circuit that latches defective column addresses read from theelectrical fuse circuit 83. If the comparison by a column decoder 52shows a match of the addresses, a redundant bit line included in thecolumn redundancy array 50 b is accessed instead of the bit line that isdesignated by the column address. If the addresses do not match, the bitline designated by the column address is simply accessed. The bit linesare accessed by selecting the corresponding sense amplifiers SA in thesense circuit 53.

The optical fuse circuit 57 includes a plurality of fuse sets. The fusesets correspond to the respective plurality of redundant bit lines inthe column redundancy array 50 b. That is, if a fuse set is programmedwith a column address and an access to that column address is requested,then the redundant bit line associated with that fuse set is accessed.Some of the fuse sets included in the optical fuse circuit 57 correspondto those included in the electrical fuse circuit 83 on a one-to-onebasis. Consequently, redundant bit lines that are specified as replacingbit lines by some of the fuse sets included in the optical fuse circuit57 can also be specified as replacing bit lines by fuse sets included inthe electrical fuse circuit 83. Note that the optical fuse circuit 57and the electrical fuse circuit 83 will not conflict with each other. Aredundant bit line is used as a replacing bit line by either one of afuse set included in the optical fuse circuit 57 and a fuse set includedin the electrical fuse circuit 83.

The sense amplifier SA selected by the column decoder 52 is connected tothe data control circuit 54 through some amplifiers (sub-amplifiers ordata amplifiers or the like) which are not shown in the drawings.Thereby, read data of 8 bits (=prefetch number) for each I/O (DQ) isoutput from the data control circuit 54 at reading, and write data of 8bits is input to the data control circuit 54 at writing. The datacontrol circuit 54 and the interface chip IF are connected in parallelthrough a TSV buffer 27 and the through silicon via TSV. The datacontrol circuit 54 includes a test circuit 54 a. The test circuit 54 amakes a pass-fail determination in a test operation, and outputs theresult of the pass-fail determination as a determination signal P/F.

The control logic circuit 63 receives an internal command ICMD suppliedfrom the interface chip IF through the through silicon via TSV1 andcontrols the row control circuit 61 and the column control circuit 62,based on the internal command ICMD. The control logic circuit 63 isconnected to a layer address comparing circuit (chip informationcomparing circuit) 47. The layer address comparing circuit 47 detectswhether the corresponding core chip is target of access, and thedetection is performed by comparing the layer address EXA which is apart of the address signal supplied from the interface chip IF throughthe through silicon via TSV1 and a layer address LID (chipidentification information) set to the layer address generating circuit46. The layer address EXA supplied from the interface chip IF is inputto the core chips CC0 to CC7 through respective input receivers 49.

In the layer address generating circuit 46, unique layer addresses areset to the core chips CC0 to CC7, respectively, at initialization. Amethod of setting the layer addresses is as follows. First, after thesemiconductor device 10 is initialized, a minimum value (0, 0, 0) as aninitial value is set to the layer address generating circuits 46 of thecore chips CC0 to CC7. The layer address generating circuits 46 of thecore chips CC0 to CC7 are cascade-connected using the through siliconvias TSV2 of the type shown in FIG. 24B, and have increment circuitsprovided therein. The layer address (0, 0, 0) that is set to the layeraddress generating circuit 46 of the core chip CC0 of the uppermostlayer is transmitted to the layer address generating circuit 46 of thesecond core chip CC1 through the through silicon via TSV and isincremented. As a result, a different layer address (0, 0, 1) isgenerated. Hereinafter, in the same way as the above case, the generatedlayer addresses are transmitted to the core chips of the lower layersand the layer address generating circuits in the core chips incrementthe transmitted layer addresses. A maximum value (1, 1, 1) as a layeraddress is set to the layer address generating circuit of the core chipCC7 of the lowermost layer. Thereby, the unique layer addresses are setto the core chips CC0 to CC7, respectively.

The layer address generating circuit 46 is supplied with a defectivechip signal DEF2 from an inactivation circuit 36. The inactivationcircuit 36 is a circuit that is activated when a defective chip signalDEF1 is supplied from the defective chip information holding circuit 33of the interface chip IF through the through silicon vias TSV3. As thedefective chip signal DEF1 is supplied to the individual core chips CC0to CC7 using the through silicon via TSV3 of the type shown in FIG. 24C,the defective chip signals DEF1 can be supplied to the core chips CC0 toCC7, individually. The defective chip signal DEF1 is activated when thecorresponding core chip is a defective chip. When the defective chipsignal DEF1 is activated, the layer address generating circuit 46transmits, to the core chip of the lower layer, a non-incremented layeraddress, not an incremented layer address. The defective chip signalDEF2 is also supplied to the control logic circuit 63. When thedefective chip signal DEF2 is activated, the control logic circuit 63 iscompletely halted. Thereby, the defective core chip performs neitherread operation nor write operation, even though an address signal or acommand signal is input from the interface chip IF.

An output of the control logic circuit 63 is also supplied to a moderegister 64. When an output of the control logic circuit 63 shows a moderegister set, the mode register 64 is updated by an address signal.Thereby, operation modes of the core chips CC0 to CC7 are set.

Each of the core chips CC0 to CC7 has an internal voltage generatingcircuit 72. The internal voltage generating circuit 72 is provided withpower supply potentials VDD and VSS. The internal voltage generatingcircuit 72 receives these power supply potentials and generates variousinternal voltages. As the internal voltages that are generated by theinternal voltage generating circuit 72, an internal voltage VPERI (≈VDD)for operation power of various peripheral circuits, an internal voltageVARY (<VDD) for an array voltage of the memory cell array 50, and aninternal voltage VPP (>VDD) for an activation potential of the word lineWL are included. In each of the core chips CC0 to CC7, a power-ondetecting circuit 71 is also provided. When the supply of power isdetected, the power-on detecting circuit 71 resets various internalcircuits.

The above description is the basic circuit configuration of the corechips CC0 to CC7. In the core chips CC0 to CC7, the front end unit foran interface with the external device is not provided. Therefore thecore chip cannot operate as a single chip in principle. However, if thecore chip never operates as the single chip, an operation test of thecore chip in a wafer state may not be performed. This means that thesemiconductor memory device 10 cannot be tested, before the interfacechip and the plural core chips are fully assembled. In other words, theindividual core chips are tested when testing the semiconductor memorydevice 10. When unrecoverable defect exists in the core chips, theentire semiconductor memory device 10 is led to be unavailable. In thisembodiment, in the core chips CC0 to CC7, a portion of a pseudo frontend unit, for testing, that includes some test pads TP and a test frontend unit of a test command decoder 65 is provided, and an address signaland test data or a command signal can be input from the test pads TP. Itis noted that the test front end unit is provided for a simple test in awafer test, and does not have all of the front end functions in theinterface chip. For example, since an operation frequency of the corechips is lower than an operation frequency of the front end unit, thetest front end unit can be simply realized with a circuit that performsa test with a low frequency.

Kinds of the test pads TP are almost the same as those of the externalterminals provided in the interposer IP. Specifically, the test padsinclude a test pad TP1 to which a clock signal is input, a test pad TP2to which an address signal is input, a test pad TP3 to which a commandsignal is input, a test pad TP4 for input/output test data, a test padTP5 for input/output a data strobe signal, and a test pad TP6 for apower supply potential.

A common external command (not decoded) is input at testing. Therefore,the test command decoder 65 is also provided in each of the core chipsCC0 to CC7. Because serial test data is input and output at testing, atest input/output circuit 29 and a test FIFO circuit 28 are alsoprovided in each of the core chips CC0 to CC7. At testing, a DFT circuit66 is used which is included in each of the core chips CC0 to CC7.

This is the entire configuration of the semiconductor device 10. Becausein the semiconductor device 10, the 8 core chips of 1 Gb are laminated,the semiconductor device 10 has a memory capacity of 8 Gb in total.Because the chip select signal /CS is input to one terminal (chip selectterminal), the semiconductor memory device is recognized as a singleDRAM having the memory capacity of 8 Gb, in view of the controller.However, a memory capacity of the core chip is not restricted inparticular.

Next, a method of replacing defective cells included in the core chipsCC0 to CC7 will be described.

The replacement of defective cells is performed thrice in the process ofmanufacturing the semiconductor device 10. The first replacement isperformed in a wafer process, and the second and third are performed inan assembly process. The replacement in the wafer process is performedby using the optical fuses 55 and 57 in order to repair defects thatoccur in the wafer process. The replacement in the assembly process isperformed by using the electrical fuse circuit 83 in order to repairdefects that occur in the assembly process. In other words, thereplacement in the wafer process stores defective addresses into thecore chips CC0 to CC7 themselves. The replacement in the assemblyprocess stores defective addresses into the interface chip IF.

Turning to FIG. 30, at first, the core chips CC0 to CC7 in a wafer stateare subjected to an operation test to detect defective addresses (stepS50). The defective addresses detected are analyzed in a tester outsidethe semiconductor device 10, whereby replacement data is determined. Thereplacement data refers to information that identifies the word lines orbit lines to be replaced and the word lines or bit lines to replace. Theword lines or bit lines to be replaced are identified by row addressesor column addresses. The word lines or bit lines to replace areidentified by the addresses of fuse sets to be used in the optical fusecircuits 55 and 57.

Next, the optical fuse circuits 55 and 57 are programmed based on thereplacement data (step S51). Specifically, laser beam irradiation isperformed by using a laser trimmer, whereby predetermined fuse setsincluded in the optical fuse circuits 55 and 57 are programmed with rowaddresses that represent the word lines to be replaced or columnaddresses that represent the bit lines to be replaced. Steps S50 and S51correspond to primary repair. The completion of the replacementoperation in the wafer process is followed by wafer dicing (step S52).Meanwhile, the electrical fuse circuit 83 in the interface chip IF isfabricated in a step separate from the setting steps of the core chipsCC0 to CC7 (step S53).

Next, the separated pieces of the core chips CC0 to CC7 and theinterface chip IF are stacked on each other and packaged as shown inFIG. 23 (step S54). After the packaging, the second operation test isperformed to detect defective addresses (step S55). The first operationtest performed in the wafer state and the replacement of defective cellsbased on the operation test ensure that all the addresses of the corechips CC0 to CC7 to be stacked are normally accessible. However, newdefective addresses may occur due to load during packaging and the loadof a burn-in test. The second operation test is performed to detect andrepair such new defective addresses that occur after the end of thefirst operation test. The second operation test is performed by usingthe analysis circuit 82 a and the analysis memory 82 b.

Next, the electrical fuse circuit 83 is programmed based on thedefective addresses detected (step S56). Specifically, an electricalfuse controller (to be described later) included in the electrical fusecircuit 83 is used to apply a high voltage, whereby the fuse setsincluded in the electrical fuse circuit 83 are programmed with rowaddresses that represent the word lines to be replaced or columnaddresses that represent the bit lines to be replaced. Steps S55 and S56correspond to secondary repair.

After the completion of the secondary repair, a third operation test isperformed to detect defective addresses (step S57). Thesecondary-repaired semiconductor devices 10 are already relieved of thedefective addresses resulting from the diffusion process and thedefective addresses resulting from the assembly process. Since theoperation tests in the primary repair and the secondary repair are notperformed at the maximum design speed, there is still a possibility ofdefective addresses that occur only under fast access. The thirdoperation test is performed to detect and relieve such undiscovereddefective addresses. The third operation test is performed by using anexternal tester 200.

Next, the electrical fuse circuit 83 is programmed based on defectiveaddresses detected (step S58). This step is the same as in the secondaryrepair. The electrical fuse controller is used to apply a high voltage,whereby the fuse sets included in the electrical fuse circuit 83 areprogrammed with row addresses that represent the word lines to replaceor column addresses that represent the bit lines to replace. Steps S57and S58 correspond to tertiary repair. This completes the series ofreplacement operations, and the semiconductor device 10 is shipped as aconfirming product.

Turning to FIG. 31, at first, one of the core chips CC0 to CC7 isselected (step S60), and an operation test is performed thereon (stepS61). In the operation test, the data control circuit 54 (test circuit54 a) in that core chip CC0 to CC7 makes pass-fail determinations. Theresulting determination signal P/F is transferred to the analysiscircuit 82 a in the interface chip IF through the through silicon viasTSV1, and analyzed by the analysis circuit 82 a (step S62). The analysiscircuit 82 a analyzes the defective addresses to generate replacementdata so that all the defective cells found can be replaced with asmaller number of redundant word lines or redundant bit lines. Aconcrete method of analysis is as explained in detail in the first andsecond embodiments. The replacement data includes information onreplacing word lines or bit lines, which are identified in terms of theaddresses of fuse sets to be used in the electrical fuse circuit 83.

If the analysis shows that the replacement is not possible even by usingall the fuse sets (step S63: NO), the semiconductor device 10 is handledas a defective product (step S67). Even if the replacement is possibleby using fuse sets in the electrical fuse circuit 83, the semiconductordevice 10 may also be handled as a defective product (step S67) when thefuse sets to be used in the electrical fuse circuit 83 are alreadyassigned to the used fuse sets in the optical fuse circuits 55 and 57(step S64: NO). If neither is the case, predetermined fuse sets in theelectrical fuse circuit 83 are programmed with row addresses thatrepresent the word lines to be replaced or column addresses thatrepresent the bit lines to be replaced (step S65). As a result, newdefective addresses occurring in the core chip are repaired.

Such an operation is performed on all the core chips CC0 to CC7 insuccession. If the foregoing operation is completed on all the corechips CC0 to CC7 (step S66: YES), the secondary repair is completed.

Turning to FIG. 32, initially, a plurality of semiconductor devices 10to be subjected to tertiary repair and the external tester 200 areconnected as shown in FIG. 21, and an operation test is performed inparallel (step S90). The operation test is performed at the maximumdesign speed. The external tester 200 evaluates whether there is anydefective semiconductor device 10 (step S91 a).

If there is no defective semiconductor device 10 (step S91 a: NO), theprocessing ends. On the other hand, if there is any defectivesemiconductor device (step S91 a: YES), the external tester 200 issues atest command so that all the semiconductor devices 10 enter a test modefor tertiary repair (step S92).

Next, the external tester 200 changes the data mask signal DM of one ofdefective semiconductor devices 10 to a high level (step S93 a). Theexternal tester 200 then selects one of the core chips CC0 to CC7 with alayer address (step S94), and outputs a detected defective address (stepS95). The defective address is input to all the semiconductor devices10, but is valid only to the semiconductor device 10 in which the datamask signal DM is at a high level. The defective address is ignored bythe other semiconductor devices 10 where the data mask signal DM is at alow level. The defective address is input to all the core chips CC0 toCC7 in the semiconductor device 10 where the data mask signal DM is at ahigh level. Again, the defective address is valid only to the one of thecore chips CC0 to CC7 that is selected with the layer address, andignored by the other core chips.

Such processing is performed on all defective addresses found in thatcore chip of the semiconductor device 10 (step S96: NO) and thenissuance of a write command for electrical fuses (step S97).Consequently, the defective addresses that are stored into the analysismemory 82 b through the analysis circuit 82 a are written into theelectrical fuse circuit 83.

The foregoing processing is performed on each of all the core chips thatare found to be defective. When the processing on all the core chips iscompleted (step S98: NO), the tertiary repair on the semiconductor chip10 is completed. The foregoing processing is performed on each of allthe semiconductor devices 10 that are found to be defective. When theprocessing on all the semiconductor devices 10 is completed (step S99:NO), the series of tertiary repair is completed.

This completes the series of replacement operations, and thesemiconductor devices 10 are shipped as confirming products.

Turning to FIG. 33, the operation of loading the replacement data isperformed in response to when the reset signal /RESET supplied to thecommand terminal 12 f changes to a high level (step S71). When the resetsignal /RESET changes to the high level, the load circuit 85 included inthe interface chip IF is activated to read the replacement dataprogrammed in the electrical fuse circuit 83 (step S72). The replacementdata read from the electrical fuse circuit 83 is serial-converted by theserializer 84, and transferred to each of the core chips CC0 to CC7through the through silicon vias TSV1 (step S73). When the serializer 84transfers the replacement data, the layer address buffer 48simultaneously transfers a layer address EXA. The replacement data,which is supplied in common to the core chips CC0 to CC7, is therebyenabled only for the core chip that is designated by the layer addressEXA. The replacement data is latched into the defective address latchcircuits 56 and 58 included in that core chip. When all the pieces ofreplacement data are transferred to the respective corresponding corechips CC0 to CC7, the series of transfer operations are completed (stepS74).

Turning to FIG. 34, the electrical fuse circuit 83 is provided for eachbank. Since the present embodiment has an 8-bank configuration, theelectrical fuse circuit 83 is divided into eight electrical fusecircuits 83-0 to 83-7, which correspond to bank 0 to bank 7,respectively. The electrical fuse circuits 83-0 to 83-7 have the samecircuit configuration. FIG. 34 representatively shows only the circuitconfiguration of the electrical fuse circuit 83-0.

The electrical fuse circuit 83-0 includes a plurality of fuse sets 83-00to 83-07 which are allocated to the core chips CC0 to CC7, respectively.The fuse sets 83-00 to 83-07 each include a plurality of fuse setsintended for row addresses and column addresses. The fuse sets areprovided with respective corresponding control circuits 83 a, which readand write the fuse sets under the control of an electrical fusecontroller 83 b. Data to be written to the fuse sets and data read fromthe fuse sets are transmitted and received through a transfer controlcircuit 83 c.

Each fuse set includes a plurality of electrical fuses. Electrical fusesare electrically-writable memory elements, preferably a nonvolatile andirreversible one-time ROM. For a one-time ROM, it is preferred to useantifuse elements in which data is stored in terms of the presence orabsence of a dielectric breakdown (breakdown of an insulating film) dueto application of a high voltage.

The data read through the transfer control circuit 83 c isserial-converted by the serializer 84 before transferred to the corechips CC0 to CC7 through the through silicon vias TSV. The data to bewritten to the electrical fuse circuit 83 is supplied from the controllogic 32 and the analysis memory 82 b, and programmed into predeterminedfuse sets under the control of the electrical fuse controller 83 b. Theelectrical fuse controller 83 b thus functions as a programming circuitthat programs the electrical fuse sets.

Turning to FIG. 35, the defective address latch circuit 56 includes alatch circuit 56 a that latches replacement data read from an opticalfuse circuit 55, and a latch circuit 56 b that latches replacement dataread from the electrical fuse circuit 83. A data control circuit 56 cand a data latch circuit 56 d are arranged in the stage prior to thelatch circuit 56 b. Under the control of the circuits 56 c and 56 d, thereplacement data transferred from the interface chip IF through thethrough silicon vias TSV is latched into the latch circuit 56 b.

The output of the latch circuit 56 a and the output of the latch circuit56 b are supplied to a select circuit 56 e. The select circuit 56 e is acircuit that selects either one of the outputs of the latch circuit 56 aand the latch circuit 56 b. The replacement data selected is supplied toa row decoder 51. The select circuit 56 e makes the selection based onflag information to be described later. The row decoder 51 includes anaddress comparison circuit 51 a, which compares the replacement dataselected by the select circuit 56 e with an access-requested rowaddress. If the two match, a redundant word line included in a rowredundancy array 50 a is accessed instead of the word line that isdesignated by the row address. If the addresses do not match, the wordline designated by the row address is simply accessed.

The defective address latch circuit 58 on the column side has the samecircuit configuration as that of the defective address latch circuit 56described above. Redundant description will thus be omitted.

As mentioned above, the replacement data transferred from the interfacechip IF is supplied in common to the core chips CC0 to CC7. The corechips CC0 to CC7 therefore need the layer address EXA in order todetermine whether or not to accept the transferred replacement data. Forthat purpose, as shown in FIG. 36, the replacement data and the layeraddress EXA are simultaneously transferred to the core chips CC0 to CC7.The replacement data supplied in common to the core chips CC0 to CC7 isthereby enabled only for the core chip that is designated by the layeraddress EXA. More specifically, the data control circuit 56 c and thedata latch circuit 56 d are activated to perform the processing ofwriting the transferred replacement data into the latch circuit 56 bonly when the layer address EXA matches the layer address LID unique toeach core chip CC0 to CC7. The series of transfer operations areperformed in synchronization with the internal clock signal ICLK whichis generated in the interface chip IF.

As has been described, the electrical fuse circuit 83 is divided intothe electrical fuse circuits 83-0 to 83-7 by bank. The electrical fusecircuits 83-0 to 83-7 each include a plurality of fuse sets 83-00 to83-07 which are allocated to the core chips CC0 to CC7, respectively.Turning to FIG. 37, the electrical fuse set 83-00 includes (X+1) fusesets, whereby (X+1) row addresses (or column addresses) can be stored.

As shown in FIG. 37, each defective address latch circuit 56 includes(N+1) latch circuits 56 a and (X+1) latch circuits 56 b. The (N+1) latchcircuits 56 a correspond to zeroth to Nth optical fuse sets,respectively. Of these, the latch circuits 56 a corresponding to thezeroth to (N−1−X)th optical fuse sets have no latch circuit 56 b to bepaired with, and thus have no corresponding select circuit 56 e.

On the other hand, the latch circuits 56 a corresponding to the zerothto (N−X)th optical fuse sets have latch circuits 56 b to be paired with.Specifically, the latch circuits 56 b corresponding to the Xth to zerothelectrical fuse sets are allocated to the zeroth to (N−X)th optical fusesets, respectively. Select circuits 56 e are provided for such latchcircuits 56 a and 56 b, so that the outputs of either ones of the latchcircuits 56 a and 56 b are selected. Replacement data transferred fromthe interface chip IF is latched into specified latch circuits 56 bunder the control of a fuse select circuit 56 s.

The outputs of the latch circuits 56 a and 56 b are supplied to theaddress comparison circuits 51 a. If an output matches an access-requestaddress, the corresponding redundant word line RWL is accessed.

As has been described, the optical fuse circuits 55 are programmed instep S51 shown in FIG. 30. The electrical fuse circuit 83 is programmedin steps S56 and S58 shown in FIG. 30. That is, the optical fusecircuits 55 are programmed first, and fuse sets remaining unused in stepS11 are used by the electrical fuse circuit 83 for alternative use. Insuch a configuration, no conflict is allowed between the redundant wordlines that are selected by the optical fuse circuits 55 and theredundant word lines that are selected by the electrical fuse circuit83. In order to avoid such a conflict and in order for the electricalfuse circuit 83 to use the remaining fuse sets for alternative use moreefficiently, the present embodiment is configured so that, as shown inFIG. 38, the optical fuse circuits 55 are programmed by using theoptical fuse sets from the zeroth in succession (arrow LF). On the otherhand, the electrical fuse circuit 83 is programmed by using theelectrical fuse sets from the zeroth, which is paired with the Nthoptical fuse set, in succession (arrow AF). This makes it possible forthe electrical fuse circuit 83 to efficiently use the remaining fusesets for alternative use.

Turning to FIG. 39, the circuit example is suitably applied to the rowside. The circuit example shown in FIG. 43 includes 14 latch circuits 56a and 14 latch circuits 56 b which correspond to the bits A0 to A13 of arow address, respectively. The outputs of the latch circuits arecompared with the respective corresponding bits of the row address bythe EXNOR circuits. The outputs of the EXNOR circuits corresponding tothe latch circuits 56 a are collected by an AND gate circuit and outputas an optical fuse hit signal LFHIT. Similarly, the outputs of the EXNORcircuits corresponding to the latch circuits 56 b are collected by anAND gate circuit and output as an electrical fuse hit signal AFHIT.

The optical fuse hit signal LFHIT and the electrical fuse hit signalAFHIT are supplied to the select circuit 56 e, and either one of thesignals is selected by a select signal SEL. The signal selected isoutput as a redundancy determination signal HIT. The select signal SELis generated by an AND gate circuit 56 f. The AND gate circuit 56 f issupplied with the output of a latch circuit 56 ae that latches anoptical fuse enable signal LFEN, and the output of a latch circuit 56 bethat latches an electrical fuse enable signal AFEN. The electrical fuseenable signal AFEN indicates whether the corresponding electrical fuseset is enabled or not, i.e., whether used or not. The optical fuseenable signal LFEN indicates whether the corresponding optical fuse setis enabled or not, i.e., whether used or not.

The optical fuse enable signal LFEN turns to a high level when theoptical fuse set is used. The electrical fuse enable signal AFEN turnsto a high level when the electrical fuse set is used. Consequently, whenthe optical fuse set is in use, the select signal SEL remains at a lowlevel. In such a case, the select circuit 56 e selects the optical fusehit signal LFHIT. On the other hand, when the optical fuse set is not inuse and the electrical fuse set is in use, the select signal SEL turnsto a high level and the select circuit 56 e selects the electrical fusehit signal AFHIT.

Turning to FIG. 40, the circuit example is suitably applied to thecolumn side. The circuit example shown in FIG. 40 includes seven latchcircuits 56 a and seven latch circuits 56 b which correspond to the bitsY3 to Y9 of a column address, respectively. Unlike the circuit exampleshown in FIG. 39, the select circuit 56 e is provided for each bit. Theoutputs of the seven select circuits 56 e are compared with therespective corresponding bits by the EXNOR circuits. The outputs of theEXNOR circuits are collected by an AND gate circuit 56 g and output as aredundancy determination signal HIT.

The select signal SEL is supplied in common to the seven select circuits56 e. The select signal SEL is generated by the AND gate circuit 56 f.As has been described with reference to FIG. 39, the select signal SELremains at the low level when the optical fuse set is in use. In such acase, the select circuits 56 e select the optical-fuse side. On theother hand, when the optical fuse set is not in use and the electricalfuse set is in use, the select signal SEL turns to the high level andthe select circuits 56 e select the electrical-fuse side.

The output of the latch circuit 56 ae that latches the optical fuseenable signal LFEN and the output of the latch circuit 56 be thatlatches the electrical fuse enable signal AFEN are supplied to an ORgate circuit 56 h. The output of the OR gate circuit 56 h is input tothe AND gate circuit 56 g. Consequently, when neither of the opticalfuse set and the electrical fuse set is in use, the redundancydetermination signal HIT is fixed to an inactive state.

It is apparent that the present invention is not limited to the aboveembodiments, but may be modified and changed without departing from thescope and spirit of the invention.

The technical concept of the present invention may be applied to asemiconductor device that includes a core chip or core chips pertainingto volatile and nonvolatile memory cells and an interface chip forcontrolling the core chip(s). It should be noted that the forms of thecircuits in the circuit blocks disclosed in the drawings and othercircuits for generating control signals are not limited to the circuitforms disclosed in the embodiment.

The technical concept of the voltage level shift circuit of the presentinvention may be applied to various semiconductor devices. For example,the present invention may be applied to semiconductor products ingeneral, including functions as CPUs (Central Processing Units), MCUs(Micro Control Units), DSPs (Digital Signal Processors), ASICs(Application Specific Integrated Circuits), ASSPs (Application SpecificStandard Products), and memories. Examples of the product types of thesemiconductor devices to which the present invention is applicableinclude an SOC (System On Chip), MCP (Multi Chip Package), and POP(Package On Package). The present invention may be applied tosemiconductor devices that have any of such product types and packagetypes.

When the transistors are field effect transistors (FETs), various FETsare applicable, including MIS (Metal Insulator Semiconductor) and TFT(Thin Film Transistor) as well as MOS (Metal Oxide Semiconductor). Thedevice may even include bipolar transistors.

In addition, an NMOS transistor (N-channel MOS transistor) is arepresentative example of a first conductive transistor, and a PMOStransistor (P-channel MOS transistor) is a representative example of asecond conductive transistor.

Many combinations and selections of various constituent elementsdisclosed in this specification can be made within the scope of theappended claims of the present invention. That is, it is needles tomention that the present invention embraces the entire disclosure ofthis specification including the claims, as well as various changes andmodifications which can be made by those skilled in the art based on thetechnical concept of the invention.

What is claimed is:
 1. A method for manufacturing a memory devicecomprising the steps of: performing a first operation test on a memoryarray formed on a semiconductor wafer; analyzing addresses of firstdefective memory cells detected by the first operation test to identifyfirst defective addresses; performing primary replacement to replace thefirst defective memory cells with first redundant memory cells based onthe first defective addresses; dicing the semiconductor wafer afterperforming the primary replacement to obtain a memory chip on which thememory array is integrated; packaging a plurality of semiconductor chipsincluding at least the memory chip to obtain a packaged memory device;performing a second operation test on the packaged memory device;analyzing addresses of second defective memory cells detected by thesecond operation test to identify second defective addresses; andperforming secondary replacement to replace the second defective memorycells with second redundant memory cells based on the second defectiveaddresses.
 2. The method of claim 1 wherein performing primaryreplacement comprises programming optical fuses with first defectiveaddresses.
 3. The method of claim 2 wherein performing secondaryreplacement comprises programming electrical fuses with second defectiveaddresses.
 4. The method of claim 1 wherein performing secondaryreplacement comprises programming electrical fuses with second defectiveaddresses.
 5. The method of claim 1 wherein first defective addressescomprise row addresses and column addresses.
 6. The method of claim 1wherein second defective addresses comprise row addresses and columnaddresses.
 7. The method of claim 1 wherein packaging comprises stackingthe plurality of semiconductor chips.
 8. The method of claim 7 whereinthe plurality of semiconductor chips are connected with through siliconvias.
 9. The method of claim 1 wherein the plurality of semiconductorchips comprises a control circuit.
 10. The method of claim 9 wherein thecontrol circuit performs the second operation test.
 11. The method ofclaim 9 wherein the control circuit comprises fuses for performingsecondary replacement.
 12. The method of claim 11 wherein the fuses forperforming secondary replacement are electrical fuses.
 13. The method ofclaim 1 wherein the memory device is a DRAM.